Consultation - Value Engineering

Pearson Fiberglass Pilings FAQs


faqs in general attachments/hardware faqs
monopile faqs
foundation piling faqs
pile driving faqs
boat house/boat lift faqs
repair faqs
environmental faqs



FAQs in General

 


How long will the pilings last in salt water?


We expect the life of the piles to be 100 years plus (fresh or salt water), given that the fiberglass sailboats we built 50 years ago are still afloat – and our resin systems are much, much better today.

 

 


Is there any maintenance on the pilings?


No maintenance is required unless there is excessive wear due to the rubbing and chafing caused by boats, dock hardware and hoops, etc.  We supply rub rails in the same color as the exterior PPT that can be attached to the pile with Tek® screws.  There will be no structural damage if the PPT is destroyed, but you do not want to chafe through the fiberglass wall.

 



How can I install the pilings?

The most common method is to use a vibratory hammer with a sheet pile clamp.  Pipe clamps may also be used with a vibratory hammer, but the clamp pressure needs to be reduced and there will be more waste for the cut-offs.  Drop hammers and diesel hammers are also used, generally in the range of 15,000 to 60,000 ft/lbs of energy.  PEARSON PILINGS drive more efficiently than wood or steel pilings!  Water-jetting can be used, but the lateral stability of the pile is lower because the soil is no longer compacted – cross bracing may then be required.

 



Will barnacles grow on the pilings?


Since the pilings are inert, marine growth is not affected in any way, except that growth can be scraped from the piles relatively easily, but barnacles will be difficult to remove if left for any length of time.  Of course, PEARSON PILINGS are impervious to any borers and worms!



Do I need to cap the piles after installation?


It is not necessary to use pile caps, but there may be some odors and insects associated with the stagnant water inside.  Some have drilled a ½” hole in the side of the pile at low water to avoid stagnant water inside the pile.

 



Do I need to cross brace the pilings?


Typically, no.  Cross bracing is generally only needed if there are very high lateral loads, such as those caused by commercial vessels and stabilize a structure that rests on rock.  Cross bracing is used primarily to transfer the loads between wooden piles due to the lower strength of the wood.  Cross bracing also can increase the uplift from ice

 



What is the load bearing capacity of a 12” Pearson pile?


The wall thickness of our 10” diameter pile is .31” and the 12” and 14” are both .375”.  The ultimate load capacities vary dependent upon cantilever length, but, generally speaking, the 10” is used in 5 ton to 26 ton applications, the 12” is used up to 30 tons and the 14”  up to 40 tons.  The load capacity at compressive yield for a short length 10” composite pile can be as high as 40 tons, but I would be hard pressed to say that is a reasonable application.

 



How do I cut the piles?


The easiest and best way to cut through our piles is with a radial (Skil®) saw with a carbide tipped blade.  It should have a minimum of 3 teeth per inch, 4 teeth is better.  Our band saw uses a 1-1/4” wide blade with 3 teeth per inch but I wonder if a small portable band saw might work at 3 or 4 teeth/inch.  If you use a short section and slice it lengthwise, it makes a good snap-on guide for straight cuts with a Skil® saw.



What is the best way to drill the PEARSON PILINGS?


For small diameter holes up to 1” a standard metal cutting bit will work just fine.  For larger diameter holes, a standard hole saw with 4 to 6 threads per inch (the normal hardware store variety) will work well for about 50 holes.



Does Pearson provide engineering assistance for dock/pier design?


We can provide recommendations as to pile diameter, spacing, attachment methods, general layout – provided we know water and soil conditions to some degree and water depth and typical use.  We cannot put a P.E. stamp on any drawings, but we can supply simple layout and general drawings that could be used for permitting.

 



What are the two ribs inside the piling?


Those are PVC extrusions used in our manufacturing process; they are non-structural and do not affect performance one way or the other.



How does ice affect the pilings?


Ice has little effect on the pilings.  The PPT exterior has a low coefficient of friction with ice (like UHMW or Delrin®) and since the pile is uniform in shape, there is little for the ice to grip.  The biggest advantage over wood piles in ice is the dramatic increase in uplift capacity, followed by the superior strength of the composite piles.



Can the composite piles be used for telescoping applications?


We have had numerous conversations about telescoping piles, but have not put anything into practice.  There is a question of water depth at the lowest compared to flood stage, but a 10 inch pile could be driven into the ground and a 12” pile attached to the floating dock.  Making a true telescoping system with 8”, 10”, 12” and 14” should be feasible, but the hardware would have to be custom fabricated – I would think out of UHMW.



What are the environmental effects of composite piles?
Can anything leach out of the piles?


There is extremely low water vapor transmission, very low moisture absorption and no solubility in water in any of the materials that make up our composite piles.  One of our primary criteria in the development of our piles is that they must be inert and unaffected by the environment – and that they have no deleterious affect on the environment.

We have MSDS’s for the piling as a complete unit and also the two polymer materials we use.  The polymer that is the exterior of the piles is widely available in medical grades is non-toxic, hydrolytically stable and inert at less than 300 F., although it can be attacked by low molecular weight solvents and some chlorinated solvents.  The outer skin is impervious to diesel fuel and gasoline.

 



We are building a pier where 3 piles will need to be in rip-rap.  The rocks are 2 to 4 foot in diameter and will be removed for pile installation.  What would be the recommendations for filling the piles or cementing them in place?  Should we build a wood box around the piles?

If the piles are being driven to some resistance prior to backfilling w/ stone I would recommend filling the piles with sand up to the level of stone fill.  There could be some localized damage otherwise, but it would not affect the integrity of the pile overall.  The wood frame approach would cause the pile to shift as the wood deteriorates and the composite will take higher loads than the wood, anyway. False work should be used during the back-fill operation, but 2x6’s should be adequate.

If the piles are not driven and are held in place only by the back-filled stone you will need to build false-work for each pile (much heavier than you would normally do for driving in rocky till).  Again, fill the pile with sand or aggregate up to the stone fill level before back-filling with the stone to minimize impact damage. 

 



Does filling the PEARSON PILE with reinforced concrete increase the structural capacity?


The load bearing capacity will be increased by some percentage (based on pile diameter), but not significantly.  A 14” pile driven to refusal may have an initial capacity of between 60,000 lbs. and 90,000 lbs. depending on hammer energy and skin friction with the soil.  Filling this pile will not change the skin friction but, on the plus side, it will increase the inertia (mass) of the pile to dampen lateral accelerations. 

We have found that filling the pile with concrete will increase the stiffness somewhat, but it will not increase the lateral load capacity at all because the concrete will crack long before the composite starts to assume the load. 

 



Can I use PEARSON PILINGS for a dolfin?

Yes, our piles have the stiffness of wood with 5 times the yield under high loads.  The piles in a dolphin can be strapped together using steel cable, as is typical, but short sections of our wear strips would have to be attached under the steel cable.  These are inexpensive and easy to install.



How much longer will a PEARSON PILE last compared to concrete?


It is hard to be definitive about the life expectancy of a concrete pile – fresh water performance is better than salt water performance; freeze/thaw cycles will deteriorate the concrete more rapidly; dynamic loading both in driving and lateral force can fail the concrete;  the steel reinforcement, while epoxy coated, will corrode rapidly if the concrete has any compression or tension cracks; an unreinforced concrete pile must be significantly larger in section, but less prone to fresh water damage.  That was sort of a long answer – in short:  The composite pile has a probable life of 100 to 300 years, exclusive of the surface finish, while the concrete pile has a probable life of 15 to 20 years.



I am thinking that it would be best to pump out all piles after install into bottom, removing water and allowing time to dry out.  Then use a cap design that will seal inside area air tight, moisture tight.  That it would be better to maintain the inside of the pile free from moisture?


There is absolutely no reason to pump out or otherwise remove the plug of soil from the inside of the pile, and also no reason to eliminate water.  The piling interior and exterior are not affected by salt water, fresh water, ice, etc. over any time period.  There is also no reason to use a water-tight or vapor-tight cap.



We are looking at using your pilings for a high altitude transmission repeater.  What are the electrical properties and what happens to them during lightning strikes?


The capacitance in the composite pile is very low, and its dielectric strength very high, but standard grounding techniques can be used to ground metal equipment.  The only experience I have had with lightning strikes on composite materials is with carbon fiber masts and wet wind turbine blades.  In the case of the all fiberglass wind turbine blades there was little damage since it was a surface charge that was transmitted to the machinery.  Carbon fiber is conductive and when struck by lightning has a tendency to burn a small area at the points of contact with some degradation of the laminate due to micro-arcing and heating.  In the case of fiberglass (nonconductive) there has only been evidence of metal contact points alone degrading due to the high heat of the metal. 



What should the life cycle costs of a pier be based on?


The life cycle costs of the pilings should be based on at least a 30 year life.  The rest of the pier’s components will probably need to replaced before then.

 



Does PEARSON PILINGS offer any warranty?


Yes, the pilings are guaranteed not to fail under normal installation practices.  If it is ever determined that the piling failed due to a manufacturing defect, the piling will be replaced at no additional cost excluding delivery costs.  No other piling supplier stands behind their product like PEARSON PILINGS.

BACK TO TOP

 



Attachments / Hardware FAQs

 


Can I notch the pile like a wood pile to attach a beam?


The notching of the pile to a 3 or 4 inch depth will not affect the durability or reduce the load bearing capacity, but I would be concerned about the wood deteriorating where the load is applied.  If this is for a residential dock and light duty, that load will not be of a concern to me, but for a design load of 40 psf, the wood might deteriorate over time (a few years).  The best bet when notching the pile is to place a ¼” stainless plate under the wood to distribute the load on the wood.

 



Can we use our own maintenance crew to build our pedestrian bridge after the pile driving is done?


Since the fiberglass piles are easily cut and drilled, the local crew could use a laser level and top the piles themselves using a skil saw with 3 to 4 teeth per inch. (~$20 for a 7 ¼” blade).  Since the piles are only 7#/ ft. the topping is pretty safe for them to do.  The monopole brackets can be installed by one or two men – a 7/8” hole saw is used to cut the bolt holes.  They can drill all the holes in a fiberglass pile in the time it takes to drill a single ¾” hole in a 12” timber pile.

 



Without much detail how much torque can the piles withstand? Using 10, 12, 14” piles with the piles locked in position on the base and a rig twisting at the top how much torque will it take to damage the above pile sizes?


The mode of failure would be predominately shear, and this would be at the connection point.  Without going through testing, I would estimate 9,000 ft/lbs for the 10” and 15,000 ft/lbs for both the 12” and 14” (since the 12” & 14” have the same wall thickness and material properties.  Since the piles would be somewhat interconnected, this estimate is conservative.



Can we use your piles as batters?


We have done batter piles at up to 5/12 angles.  A bolted galvanized bracket with a ¾” pin is used to connect the piles.  Please contact us regarding the mechanical arrangement and loading conditions.

 



Can I use a 14” PEARSON PILE in place of 16” Southern Yellow Pine?  We are planning on using 6 piles per dolphin.

Here is a quick thumbnail sketch – comparison of a single 14” Pearson composite pile to a single 16” Southern Yellow Pine pile.  The deflection of the composite pile is slightly more than the wood pile, but once arranged in a dolphin, I would think that the difference would be imperceptible.  The lateral load capacity is what really stands out – with 6 piles per dolphin - a rough order of magnitude guestimate.

 

27' Dolphin (6 Piles)

16" S.Y.P. Pile

14" x .375 Pearson Pile

Weight @ 50' (lbs.)

2,001

600

Max Load @ Failure 27' (lbs.)

2,420

7,500

Deflection @ 1,000 lbs. (in.)

5.2

6.6

Deflection @ 2420 lbs. (in.)

12.5

16

6 Pile Dolphin Capacity (Lateral Load @ failure)

5808

18000

 


The same steel cable approach can be used for binding the piles, I would recommend our rub strips at that area to prevent chafe.  All of the above numbers are based on a 27’ cantilever and ignore ground conditions.    

BACK TO TOP



Monopile FAQs

 


What is the maximum spacing for a monopole dock?  How heavy should the joists be?


The spacing recommendations for the monopole system are shown on a data sheet on the PEARSON PILINGS web site.  The distance between the monopole drives the wood section, i.e. a 12’ pile spacing would use 3 sets of  2x12’s or 3x10’s, a 15’ spacing would use 3x12’s, a 10’ spacing would use 3x8’s, etc.  These are just examples and the local building codes should apply.

 



What is the greatest width walkway that can be built to cantilever off the various pile sizes - 10", 12" & 14"?  


I would not recommend a cantilevered pier 8’ wide at 10’ above the ground plane even with the 14” diameter piles due to the deflection at design load of around ¼” and we would be approaching the working load of the bracket bolts.  This width would make the deck feel unstable to the people using the pier.  I am attaching our monopole height vs. pier width graph.  I believe the practical limit for monopile pier widths on our 14” pile is 6 feet due to lateral movement.

 



I was planning to through bolt the piles and use some sort of sleeve as you show in the sketches you sent. Is the black pipe you note, the black pipe used for plumbing applications? Also, is the working load for the ½” bolt 2000lbs per bolt bearing area? Or for the pair? Finally, do you recommend certain center-to-center bolt spacing in the pile?


The black pipe is difficult to cut in the field, and of course, it will not last long in a marine environment, so we have looked at plastic pipe to perform the same function.  We have done some testing using 1-1/2” Schedule 80 PVC pipe as the reinforcement to prevent the pile from going oval if the bolts are over-tightened.  The working load should be for the pair – I think the typical ½” bolt has a working load of 900# to 1000# (usually ¾” galvanized bolts are used).  The spacing of the bolts would be dependent on the wood so I would say 6 diameters (3”) minimum and 4” would be better for the timber and the pile requirements are 4 diameters.

 



The customer wants to build the walkway 6’ wide for a golf cart. Can this be obtained by using a 6X6 instead of 4X4 on top of the monopole brackets? Dock will be 2000’ 5’ exposed, and the pile in ground 10 to 15’.  We will use an 8000lb bucket to install 14” piles. Send answers and I can quote project.


At 6’ wide (monopile) he will need to use 4” x 6” cross-arms and 4 2x12 joists (he will get more lateral stiffness if he forms a truss between the joists – then he can use 3 parallel 2x12).  There will probably be settling of the pile that the machine rests on during driving, but that will depend on the driving energy and soil conditions.  If he drives to refusal every time and if he can transmit 12,000 ft lbs of energy into the pile being driven there may not be noticeable settling on the pile the machine is supported by.  The 14” diameter pile is more than adequate for this application, but there is no way that a 12” pile will provide the lateral stability on 15’ centers.

 



I have a client that wants to do a monopole through a mud flat in Ga. The structure is 4’ exposed piling, 13’ mud’ then sand. Can he use a 10” 20’ pile? The deck is 4’ wide.


I suggested, since there is no wave action he could place the monopiles on 12’ to 14’ centers and use 2” x 12” joists (3) to span.  I am comfortable with this approach in this case because it is a light duty dock.   

BACK TO TOP



 

Foundation Piling FAQs

 


Can I use composite piles for a house foundation that is designed for wood piles?


This one is easy.  The skin friction of a composite pile is approximately the same as a steel pipe pile and is significantly higher than wood.  The total vertical capacity of the composite pile is higher than the wood pile and approximates the steel pile.  The lateral capacity of the composite pile equals that of a comparable steel pile and a few times higher than that of a comparable wood pile.  I would think that if wood piles are successfully used for house foundations in your area that composite piles driven to the same depth would provide a much higher capacity.  If the structural engineer or building inspector has any questions, I would be happy to contact him.

 



Will a PEARSON PILING meet my local building code?

The local building code usually does not have requirements for foundations (outside of Massachusetts), but the foundation plans normally have to be approved by a local P.E. or building inspector. 

 



Should we fill the composite pile with concrete and rebar after driving?


Using steel rebar after the piling is driven makes post-tensioning impossible and, since the steel cage would be closer to the neutral axis, the stiffening effect (around an additional 80%) would be more costly than either using a larger diameter pile or an additional pile.

 



I am building a house on piles.  What is the load bearing capacity of PEARSON PILINGS?

I do not like to make assumptions about the load bearing capacity, without the aid of soil borings in the immediate vicinity.  That said, if the pile driver is using a drop hammer, the load bearing capacity at the time of driving can be estimated when the pile hits refusal.  For example, a drop hammer exerting 40,000 ft/lbs could give a capacity of 50,000 lbs. and higher when refusal is reached, but for the purposes of the builder, I would use the energy of the hammer as the capacity at refusal.  Depending on the soil, this

number may increase dramatically as the soil sets around the pile and increases skin friction (1.5 times to more than 2 times).  For example, a 12" diameter pile ordinarily has a capacity of 50,000 to 80,000 lbs. at the time of driving when driven to refusal - but this would be in dense clay and not silt or organic material.

 



Do I need a fiberglass cap for the top of a PEARSON PILING used in a house foundation?

We have not had occasion to use an FRP plate to cap our piles for load distribution – normally it has been steel fabrications, a galvanized angle bracket, or nothing at all.  If there is constraint on lateral movement (mechanical attachment to the pile) I do not think a protective plate would be at all necessary.



What diameter and length Pearson Pile should I use for a house foundation?


The length and size is entirely dependent upon the load requirements, pile spacing, soil conditions and height above grade.  Very few states have building codes for foundations, so it is important to have your architect or structural engineer determine the appropriate piles.  We can recommend some foundation brackets and help with the beam to pile attachment in terms of design with your architect or engineer.

 



The land in which we will be building on is shallow soil with lava rock just beneath at a depth of 5ft+-.  I will be ordering a soils report to obtain a more accurate status.  Do you know if that would prevent or cause some issue on how the Pearson pilings are driven into the ground as well as minimum depth level?


It sounds like you will have good bearing capacity from the lava rock, but I would have some concerns about uplift (this would be true with any piling material).  One way to increase uplift capacity is with earth nails or dwydag rods and washers into a drilled hole – this can be post-tensioned and the 4” or 5” hole is less inexpensive than drilling oversize sockets.  I think you should consult a local geotech about proper anchoring.

 



Are there any advantages in using Pearson Pilings for a house foundation in a seismically active area?


I will try to answer your question about seismic issues as well as I can.  Our pilings are frequently used for building foundations in flood zones and high wind zones (>100 mph 3 second gusts).  Generally speaking, our composite piles are the same stiffness as a comparable diameter wood pile while having approximately the same compressive and tensile properties of steel.  The elastic deformation limits of our composite pile are much higher than those of concrete, steel or wood, so I would think our piles would be much more durable in a seismic event.  I think the low mass of the composite pile may have a beneficial effect but the greatest benefit would probably be compliance during the shock wave. 

 



Is there anything else I need to know about moving forward on my foundation with Pearson?  Could you layout the process for me that we will be moving through?


The process is quite simple, really.  The depth the piles will be driven to needs to be determined, based on the soil conditions and local driving records.  I would like to see a general layout of the structure including elevations for a max wind load.  Your structural engineer, with input from us, will specify the attachment method used for the foundation to structure. 

BACK TO TOP



Pile Driving FAQs

 


What kind of pile drivers have you used on PEARSON PILES?

We have used drop, impact (hydraulic, pneumatic, diesel) and vibratory hammers to drive the composite piles with no problems and little or no damage to the cosmetics.  What does seem to work best with vibratory hammers is a sheet pile clamp that grips one edge of the pile – we usually insert a ¼ section of a pile cut-off to reduce cosmetic damage, but even without that we only lose 6” off the top.  Normally this is cut off when capping the piles.  A pile clamps works well, but the clamp pressure needs to be reduced and a wood plug inserted into the composite pile – the top 3 to 4 feet will have to be trimmed off.  We do not have any experience with a full encirclement grip, but I would think it will work well – the clamp pressure may need to be reduced.

 



Will the fiberglass delaminate when it is driven with a drop-hammer?


As for delaminating- the typical interlaminar strength for vacuum processed FRP is 1400 to 2400 psi – due to our needle punching, we have 10 times the interlaminar shear strength.  In other words, the damage tolerance of our piles is hugely higher than any FRP product available, boats included.

 



Do I need to use a pile tip to drive through gravel?


The answer is dependent on the soil conditions and rock size.  We have found that driving tips are not necessary for coarse till, but in the case of large (+ > 6” / 150mm) rocky gravel we have used a steel spud to open up the path.  Both steel H piles and pipe piles have been used successfully for opening up the coarse till.  We do not use pile tips because the piles drive efficiently in the soil conditions we have found.  The exceptions occur with bedrock and shale – drilling is then required.  I would think driving tips could be used for some soft sandstone and coral, but some steel straps should be welded to the inside to hold the tips in place in the composite pipe pile.  The piles drive quite efficiently through pea gravel and most till.

 



How does vibratory driving compare to drop hammer driving with a composite pile?


With a drop hammer you know the initial resistance or capacity of the driven pile.  We do not have test data comparing vibrated piles to hammer driven piles in the same ground conditions. There is no easy method for determining th e load bearing capacity of piles during installation with a vibratory hammer that I know of, and without a blow count you would need a static load test.  They could be vibrated in and a drop hammer used to drive the last couple of feet to determine capacity.  In talking to a couple of pile drivers, they felt that if the vibrated piles reached refusal with less than a 2’ penetration variation between them the values would be in the same range in inch-pounds as the hammer energy.  This may work if you have soil data and know the energy of the hammer.

 



Should a pile tip be used for driving to increase the load bearing capacity?  Does the soil inside the hollow pile have any negative effects?


The soil in the pile has some positive effect in terms of the plug contributing to the displacement capacity – we have not analyzed this since driving refusal is based on skin friction when we have done PDA’s – so the displacement value has been ignored – but this value is probably only in the range of 5 kips.  The mass of the soil in the pile would have some positive effect on the displacement in the case of lateral accelerations.

 



How well do PEARSON PILES drive? 


On our web site there is a PDA report from GZA directly comparing wood, composite and steel driving efficiencies and bearing capacities.  Pearson Composite piles drive slightly more efficiently than steel piles of comparable dimensions in clay, sand, silt, fine till etc. due to radial expansion at the energy wave.  They do not drive as well as steel through rip-rap, shale, coral, etc.

 



How much energy is needed to drive 12” PEARSON PILES? 

Typical driving forces for the 12” diameter Pearson pile are usually around 15,000 ft/lbs to 50,000 ft/lbs.  We have used higher energy levels without structural damage to the pile.  Both impact and vibratory hammers are used without cushion material. If the composite pile is driven after complete refusal, there can be some localized damage at the top; similar to steel pipe piles, but generally a high number of blows is required.

 



Do I need to use leads? 


There are typically no leads used for our 10” piles up to 40’ in length, and leads are recommended on 12” piles longer than 60’. 

BACK TO TOP



Boathouse / Boatlift FAQs

 


I am building a boat lift and need to know the capacity of the pile for a sandy area.  Will a vibratory hammer work?


An experienced pile driver can estimate capacity for a vibratory hammer as well as an impact hammer - and I would have a tendency to go with the pile drivers opinion as to what is refusal.

 



I am building a private boat house.

The boathouse will have a roof and will also support a boatlift for a 4000lb boat.  The water is about 6 ft deep and posts are normally driven 5ft into the lake bed.  Would your pilings support that type of application?


Depending on the height of the boat house roof, 10" piles on 12' centers will work - with only a 5' embedment the capacity of each pile is probably in the range of 5,000 to 12,000 lbs depending on soil conditions.

 



Here are the plans for our boathouse. What would you suggest for brackets\attachments?

Also would it be functional to use stainless steel?


Since you have 2 piles per bent for the deck around the boathouse, I would recommend through-bolting the beams to either side of the pilings with 5/8” or ¾” stainless or galvanized bolts.  In the case of the attachment of the roof beams, I would use the 4” angle brackets from Ninigret (or some other dock equipment supplier), these are galvanized steel brackets shown in the foundation testing pdf file.  Stainless will increase the longevity at the water, but galvanized bolts above the waterline are appropriate.

 



My boathouse shifted this spring – it was built on 6x6 timbers last summer.  What piles and spacing should I be using?  The boathouse is on one of the Finger Lakes.  The water depth is only 3 feet.

It would help to know boat house dimensions, sea conditions, etc. to determine pile spacing. That being said, the load bearing capacity of a short 6x6 wood pile is probably around 4,000 lbs. depending on soil conditions with our 10” diameter pile having around a 20,000 lb working load at 6 foot above grade.  (I am making assumptions based on the selection of the 6x6.)  The wind loads on the boat house will probably exceed those of the boat & lift.  The lateral load capacity of the 10” composite pile is about 20 times greater than the wood.  Your pile spacing should be in the range of 12 to 15 ft. with the composite pile.

BACK TO TOP



Repair FAQ’s

 


My contractor accidentally cut into the top of a 10” pile on my boatlift.  Can I repair the pile?  The damage is 2 feet from the top.


The method of repair is quite simple:

  1. Clean cut with acetone
  2. Scrape rough edges with a razor so there is a very slight bevel
  3. Using West® System epoxy 105 with 205 hardener mix as per instructions on label – 3 oz. (Available at West Marine)
  4. Add 3 – 4 oz. West® 404 High Density Filler (depending on temperature – you have 10 to 20 minutes before gel)
  5. Squeegee into cut
  6. Wipe smooth with rag and ethanol
  7. Leave a slight groove or indentations for the gel coat
  8. Allow to cure 24 hrs,
  9. Mix gel coat with catalyst (only a small amount is needed, but to get an accurate ratio, mix ½ teaspoon catalyst with 3 oz. gel coat (2.5grams to 90 grams)
  10. Paint onto epoxy with a disposable artist’s brush
  11. Wipe excess off with a rag and acetone
  12. Allow to cure 24 hrs.

This repair is both structural and cosmetic – the filled epoxy has a compressive yield of around 3,000 psi.  Since less than ½ of the pile is cut, I have no concerns about the piling being used for a boat lift and/or a boathouse roof.  The lateral capacity at a 10 ft cantilever from the cut would be in excess of 4,000 lbs. with the axial capacity (vertical) around 40,000 lbs. 

BACK TO TOP



Environmental FAQ’s


What are the environmental effects of composite piles? Can anything leach out of the piles?

There is extremely low water vapor transmission, very low moisture absorption and no solubility in water in any of the materials that make up our composite piles. One of our primary criteria in the development of our piles is that they must be inert and unaffected by the environment – and that they have no deleterious affect on the environment. We have MSDS’s for the piling as a complete unit and also the two polymer materials we use. The polymer that is the exterior of the piles is widely available in medical grades, is non-toxic, hydrolytically stable and inert at less than 300 F., although it can be attacked by low molecular weight solvents and some chlorinated solvents. The outer skin is impervious to diesel fuel and gasoline.



How durable is the coating on the piles?

We would estimate 20+ years for the PPT exterior before it has significant chalking and needs painting above the waterline for cosmetics only – it will not to be painted. Both the PPT and the resin are UV stable with the PPT showing no color shift for 2000 hrs. in a quv. Below the waterline the PPT should be hydrolytically stable indefinitely.



Will barnacles grow of the pilings?

Since the pilings are inert, marine growth is not affected in any way, except that growth can be scraped from the piles relatively easily, but barnacles will be difficult to remove if left for any length of time. Of course, PEARSON PILINGS are impervious to any borers and worms!

How does ice affect the pilings?

Ice has little effect on the pilings. The PPT exterior has a low coefficient of friction with ice (like UHMW or Delrin®) and since the pile is uniform in shape, there is little for the ice to grip. The biggest advantage over wood piles in ice is the dramatic increase in uplift capacity, followed by the superior strength of the composite piles.



What are the environmental effects of composite piles? Can anything leach out of the piles?

There is extremely low water vapor transmission, very low moisture absorption and no solubility in water in any of the materials that make up our composite piles. One of our primary criteria in the development of our piles is that they must be inert and unaffected by the environment – and that they have no deleterious affect on the environment. We have MSDS’s for the piling as a complete unit and also the two polymer materials we use. The polymer that is the exterior of the piles is widely available in medical grades, is non-toxic, hydrolytically stable and inert at less than 300 F., although it can be attacked by low molecular weight solvents and some chlorinated solvents. The outer skin is impervious to diesel fuel and gasoline.

style="margin-bottom: 0px"> 
BACK TO TOP