4x8 x 3/4 PVC Sht - Seeking working/handling/bonding advice

[Platonic Solid]

I'm looking at using 4x8 3/4 PVC Sheet on the lower portion of my Rat Shack (link) build.

image linked to HD​

Anyone have experience using this stuff. It's a bit pricey @ $100/sht, but it never needs painting and I can stick it into the dirt and never worry about it. I'll be cutting into 16" x 8' strips, so I'll only need 3 sheets to do the lower perimeter of the 12'x24' shed/garage. Any experience: handling, cutting, nailing, screwing, seam bonding ... appreciated.

 

[Squashfest81]

Platonic, nice topic.
Appears to be a great use of the material. I've been thinking of using the 1/2in and ripping into strips to trim out my shed project. Much cheaper and the scale may fit the little shed better.

 

[Voi]

Anyone have experience using this stuff. It's a bit pricey @ $100/sht, but it never needs painting and I can stick it into the dirt and never worry about it.

I've worked with cellular PVC quite a bit. I'd guess most of the time it was Sintra or Celtec but I'm sure there were other brands over the years.

I don't know for sure how the product you linked to differs from what I'm used to. It was easy stuff to work with.

Without reading your other thread, I assume you're using this is some sort of exterior wainscoting? So the seam bonding is to adjoin panels to make a longer panel?

If it's like what I'm used to that type of bond would be the weakness of this type of material. If I really needed to do that I would have used a batten made out of 1/8" thick solid stock of the same material and solvent bonded it to the face of the two pieces that needed to joined. Nowadays I'd probably leave a narrow gap behind the batten and fill it with some of the newer 2k plastic bonders on the market.

The reason for the batten is that a face to face bond allows for a stronger solvent bond that trying to solvent bond two foamed interior edges together.

 

[Platonic Solid]

Voi - I want to use it instead of pressure treated plywood around the bottom 16" perimeter of the shed. I figured it would be a good idea to bond the edges to form a watertight seal. I don't need the bond to be structural. I assume that PVC is PVC and I could use the typical all purpose pipe cement. I wouldn't want to use that purple primer as that would just look nasty.

 

[manwithtools]

I have not used it, but Gorilla Glue makes a combo product (primer / glue) that dries milky white I think. Reviews are good on Amazon, particularly for PVC trim. I'd get a can and try it. Can you buy products like Aztek or Versatex in widths as wide as you are after?

 

[Voi]

I figured it would be a good idea to bond the edges to form a watertight seal. I don't need the bond to be structural. I assume that PVC is PVC and I could use the typical all purpose pipe cement. I wouldn't want to use that purple primer as that would just look nasty.

The problem with bonding edges on this stuff, or at least the stuff I used, is that the solvent adhesive causes the foamed interior to melt and collapse to a certain degree so there is not a lot of surface area for bonding.

Based on my experience when using regular old PVC pipe cement face to face bonds are very strong, edge to face bonds aren't all that great and edge to edge bonds are even worse.

I'm writing all of this assuming the product at Home Depot is just like the Sintra or Celtec I used. Two thin veneers of solid PVC over a foamed interior of cellular PVC. So by overlapping two adjoining pieces with a batten you're getting the much stronger face to face bond.

The product you're looking at might be much denser on the interior and not collapse to the same degree.

 

[Platonic Solid]

Thank you Voi, that makes sense. I haven't looked at the material yet, but if it has a foamed interior then I will use a batten as you suggest. I will have to see if I can find some PVC exterior corner pieces as 3 sheets cut to 16" strips is exactly how much I need. I'd like to avoid buying a 4th $100 sheet just to get a couple inches.

This is what I'm working on:

pic linked to larger image
​

 

[6768rogues]

I have used a similar product that is marketed by Azek. They have a specific glue for it that does not use primer and has a longer working time than PVC pipe cement. If you glue it with the specific glue and clamp it, it will have a very strong bond the next day.
When you cut it, it makes tons of white PVC sawdust that does not go away. I attach a vacuum to my table saw to catch as much as I can.

 

[Platonic Solid]

As far as attaching the PVC sheet to the framing, which is better: screws or nails?
Will flat head screws cause it to crack around the screw head?

 

[Platonic Solid]

Thanks 6768rogues. I found their adhesive. I'm sure it will work on the Veranda brand as well as Azek.

pic linked to HD​

 

[dvups1]

GE SCS 1000 silicone


Sent from my iPhone using Tapatalk

 

[CTyankee]

Use the Azek glue. You can use screws and fill the holes or spring for a box of the Azek screws and plugs, just don't choke when you see the price. I've used and installed literally tons of the stuff over the years....from the newer 2x4 stock....the trim stock...to all the different thickness sheets.

You might regret not painting it. It may not rot, but it's going to attract dirt, and probably develop green mold on the edges...especially the ripped edges. We will not install it without sanding and painting it. It looks less like plastic and probably should never need repainting in your lifetime. Need to avoid dark color though. JMO.

All the trim on this house is Azek...primed and painted.

 

[Platonic Solid]

That's a work of art CTyankee! I'll paint it as you recommend. I have to paint everything else in the end anyway. The instructions warn against painting dark colors also. You confirmed something I was wondering about = green mold. I've had several friends ask how best to clean the green mold off PVC fencing (I've had good success with Jomax). I figured this siding would be no different. I'd rather paint than have to clean mold from the textured surface on a regular basis.

I've recovered, or should I say become numb, from fastener sticker shock as I've been using lots of Timberlok and SPAX screws. I assume these Cortex 75-Piece Fastener Set for AZEK Trim for $20 (link) is what you're referring to. That almost sounds cheap compared to Timberloks.

 

[quattro_sinko]

I have used a similar product that is marketed by Azek. They have a specific glue for it that does not use primer and has a longer working time than PVC pipe cement. If you glue it with the specific glue and clamp it, it will have a very strong bond the next day.
When you cut it, it makes tons of white PVC sawdust that does not go away. I attach a vacuum to my table saw to catch as much as I can.

This^

Also, I strongly suggest using pocket screws to hold your **** joints together (for PVC gluing). You can bore them on the back side (interior) to pull the edges together and clamp . The only thing you want to keep in mind is that the material will expand and contract on a daily, if not seasonal basis. For jointing the corners I'd suggest using a miter cutting bit in a router, it will give you a joint as clean and bullet-proof (with PVC glue) as you could hope for. Just remember to fasten your corners to the structure as far away from the corners as you can so they have some degree of freedom of movement at the actual corner joint.

And for fastening? Buy the Cortex fasteners with the little color-keyed caps. They go on easy, counterbore themselves, have hi-lo threads to pull everything together, and the caps make finishing easy.

(not affiliated with Cortex, just a fan.)

 

[Xander]

I’ve used AZEK a decent amount. I really like it. The glue they sell works well. They also sell fasteners with drill bits and plugs that fill in the holes you make with the screws. They are not cheap, but from 2’ away you really can’t tell there are any fasteners.



Close up


From 2’ I am pointing at the plug



X...

 

[Firebrick43]

This^

Also, I strongly suggest using pocket screws to hold your **** joints together (for PVC gluing). You can bore them on the back side (interior) to pull the edges together and clamp . The only thing you want to keep in mind is that the material will expand and contract on a daily, if not seasonal basis. For jointing the corners I'd suggest using a miter cutting bit in a router, it will give you a joint as clean and bullet-proof (with PVC glue) as you could hope for. Just remember to fasten your corners to the structure as far away from the corners as you can so they have some degree of freedom of movement at the actual corner joint.

And for fastening? Buy the Cortex fasteners with the little color-keyed caps. They go on easy, counterbore themselves, have hi-lo threads to pull everything together, and the caps make finishing easy.

(not affiliated with Cortex, just a fan.)

I assume you mean a miter lock bit and not just a straight 45 degree miter bit?

I did not realize it was sold as sheets. This is good as I have to trim the garage door openings of my icf build and I thought I was going to have to glue pieces together as the walls are 12.25" thick. Is it stable enough width wise to survive?

Also are the cortex plugs/screw standard size heads. On the openings I need to attach the PVC directly to the walls concrete core with tapcons. I have a tapered drill/plug cutter from lee valley that works awesome on wood but not at all on PVC due to melting and the cellular core.

I have used some PVC trim AZEK quite a few times. Never found the dust that bad(outside). I remember the first time I routed a royal PVC door frame kit for hinges. Literally 2 hours of vigorous use of a shop vac. It was terrible. Never did that again without the shop vac hooked up to the router.

 

[atch]

For the **** joints how 'bout using thin sheet metal flashing UNDER the PVC? About 6-8" wide and slightly longer than the width of the PVC; with the bottom turned out 1/2" (or whatever the PVC thickness is). Overlap each piece of PVC over the flashing the same distance.

 

[quattro_sinko]

I assume you mean a miter lock bit and not just a straight 45 degree miter bit?

I did not realize it was sold as sheets. This is good as I have to trim the garage door openings of my icf build and I thought I was going to have to glue pieces together as the walls are 12.25" thick. Is it stable enough width wise to survive?

Also are the cortex plugs/screw standard size heads?

Yes on the miter-lock bits

The attached photo is one of 18 pedestals (36" tall, 14" wide at the body, bigger across the beveled tops and base) that I built about 10 years ago for a client. No separation at the joints yet. Similar to installing wood board and batten, plan your fastener locations to avoid creating buckle zones, and to allow slight movement. If I was jambing and casing a door opening with PVC, I'd try to fasten the jambs down the center, one line of cortex screws, PVC glue and cortex screw the case to the jamb, and fasten the case in the center to the block. (I'd try to use a sheet of 5/4" for the jamb, if possible, to give better purchase for the case screws)

I'm pretty sure Cortex caps only come in one size, but you may be able to use the smallest head tapcons if you carefuly pre-drill. Check diameters before proceeding I have made my own oversize caps using cheap plug cuttters, but it was time consuming, and they needed to be cleaned up.

FWIW, I was installing Azek decking on a job and couldn't understand how my laborer was cutting everything short, repeatedly. I'd give him a batch of numbers to cut and he kept bringing me material that was short when I went to install. It took awhile, and a bunch of comparing tape measures, we finally realized that he was cutting off a pile that had been in direct summer sunlight, and bringing them to me in the shade. By the time 10-15 minutes had passed and I was placing them to install, they had shrunk roughly 1/8" over 16' lengths.

Moral of the story is to plan for a little movement.

Edit: Picture uploads are killing me!

 

[MushCreek]

If you have enough length, make a 45 degree lap joint instead of a **** joint- much stronger. I did this throughout my house, making trim out of sheets of MDF. I cut a good 45 angle on each piece, and clamped it together with waxed paper and wood blocks. Practice without glue to be sure of your set-up. Of course, I used wood glue for my trim, not PVC. In articles I've read, regular pipe glue works fine, but you've gotta be quick. No purple primer needed.

 

[GTO]

You can use Christies White Hot Glue as a less expensive alternative.

 

[theoldwizard1]

Voi - I want to use it instead of pressure treated plywood around the bottom 16" perimeter of the shed.

At that price, I would consider 1x6 PT boards running lengthwise . Yes, it will look like a patch job compared to the upper, but it is what it is ! I assume the new cripple studs you are adding are also PT.

You could also add a couple of interior nailers and try to copy the the horizontal boards from above.

Make sure to use hot dipped galvanized or stainless steel fasteners or at least one that are approved for use with PT.

If you are going to **** joint the 1x6, put a good bead of construction adhesive on the top edge of each board. PT needs to weather for about a year before it can be painted or stained.

 

[ishiboo]

Menards makes a composite grade board which has a tongue & grove interlocking system where you can add to the bottom of it to make it taller. It probably won't be as cheap as your PVC but I think it's a lot better option.

Bottom grade board:

https://www.menards.com/main/buildi...877-c-5713.htm?tid=381136491552370716&ipos=45

6" "expansion", though for your application it seems you could just use several "expansions" to get what you want.

https://www.menards.com/main/buildi...624-c-5713.htm?tid=381136491552370716&ipos=47

 

[Platonic Solid]

theoldwizard1 - I understand what you're saying, but for a little extra money I get to learn something new and what better structure to learn on than this.

ishiboo - Menards isn't an option in CT. Looking at similar HD products, the price is excessive.

All - I assume the Cortex fasteners are rated for install in pressure treated. Not sure what the difference is (plug color?), but HD offers a Cortex fastener specifically for Veranda (link).

 

[ishiboo]

theoldwizard1 - I understand what you're saying, but for a little extra money I get to learn something new and what better structure to learn on than this.

ishiboo - Menards isn't an option in CT. Looking at similar HD products, the price is excessive.

All - I assume the Cortex fasteners are rated for install in pressure treated. Not sure what the difference is (plug color?), but HD offers a Cortex fastener specifically for Veranda (link).

Yeah, it's simply a composite grade board I provided an option to.

Remember these products - especially PVC - expand and contract.

The difference is probably plug color and material... has a more similar color/texture/etc. to match that brand of trim.

Don't ever assume something is rated for pressure treated. The product page states "ACQ approved" so you are good.

 

[6768rogues]

I have used the Azek screws and plugs. They work well but are expensive. Since you are using a different brand of sheet material, the color will probably be different. If the plugs are not the same color, they will show but in your application maybe it doesn't matter.
On the outside of my front porch, I used a trim nail gun with 16 gauge T-head nails and I bought stainless steel nails. They only leave a tiny pinhole and work well, with the stainless nails leaving no rust stains. I used 316 stainless gun nails for trim on my deck, because it is fastening into treated wood and 304 stainless can corrode in treated wood. I had some nails left so I used them to trim my porch. For around $80, you can buy a box of 316 stainless gun nails that are inert to almost everything they will ever be exposed to.
CTYankee, the trim on that house looks nice. If you did the work, you did a great job.

 

[Strouty]

You could easily buy a plug cutter and use a piece of scrap to make matching ones.

 

[Platonic Solid]

So if I have three 8ft x 16” strips running horizontal at the base - Is it better to design for material expansion or use more screws to control expansion and do the face to face solvent bonding with a vertical batten?

I have 2 possibilities rolling around my head:

1. Face to face solvent bonding then together with a vertical batten leaving 1/4" expansion room at the beginning and end of the 24ft run.

2. Leaving a 1/4” expansion gap between each panel hidden by a vertical batten – silicone calk to water proof.

 

[quattro_sinko]

**** end to **** end solvent-bonding with pocket screws (all weather epoxy coated Kreg would be my choice) pulling them together (bored on the interior side, hidden) and you should be good to go. IMHO there is no need to leave a gap (or use battons) if you do this.

 

[CTyankee]

So if I have three 8ft x 16” strips running horizontal at the base - Is it better to design for material expansion or use more screws to control expansion and do the face to face solvent bonding with a vertical batten?

I have 2 possibilities rolling around my head:

1. Face to face solvent bonding then together with a vertical batten leaving 1/4" expansion room at the beginning and end of the 24ft run.

2. Leaving a 1/4” expansion gap between each panel hidden by a vertical batten – silicone calk to water proof.

Any run over 8 ft we'll do half lap expansion joints(that's what we call them) and leave them exposed. Need to space them out equal distances to divide the run to make them look good. Keep in mind we also use a water table trim or drip cap to keep out any water if doing skirt boards.

6768rogues...TY Yes me and my boss did the whole house. All of the exterior is done in composites.:

https://www.garagejournal.com/forum/showthread.php?t=322103

 

[Platonic Solid]

Is rippling between fasteners due to expansion and contraction something I need to be concerned about?

 

[Platonic Solid]

**** end to **** end solvent-bonding with pocket screws (all weather epoxy coated Kreg would be my choice) pulling them together (bored on the interior side, hidden) and you should be good to go. IMHO there is no need to leave a gap (or use battons) if you do this.

Would you put anything in the seam to make the joint water tight?

 

[quattro_sinko]

Would you put anything in the seam to make the joint water tight?

Your joint should be water-proof provided your **** ends are in COMPLETE contact with each other when gluing. The glue will not act as a "gap filler" or span small openings though. My understanding is that the glue works on a molecular level essentially softening up the surface of the two (in this case) **** ends and "welding" or bonding them together. It essentially turns two pieces into one bigger piece. If you still have gaps after gluing, but are satisfied with the bond, I'd recommend filling them with an appropriate caulk to keep water from collecting and freezing (and expanding) within the joint. I don't think water will degrade the quality of the joint unless it were to freeze.
Speaking of freezing, I believe there were some temperature limitations on the glue and it's applications. Look on the can if you go this route, and follow the guidelines (within reason). (PS: you can wipe excess PVC glue that gets squeezed out of the joint immediately with a cloth to clean up.)



The first large project I did with PVC (1200 s.f. wrap-around porch and trim, mosty all Azek) I spent some time beforehand reading instructions, watching youTube videos, and trying to get all of the information I could to get the best, longest lasting joints. Over a decade later and it still looks good and I use the same methods today.

 

[Motown]

I'm goiung to be starting on the trim on a shed I'm doing. I bought 1x6 Azek to go around the base. Home Depot has screw kits with plugs. The kit I have below is $20.

 

[theoldwizard1]

Remember these products - especially PVC - expand and contract.

So does it require special fastening methods/products ? Most PVC is used for trim.

 

[CTyankee]

Is rippling between fasteners due to expansion and contraction something I need to be concerned about?

No. 95% of our work is done using Azek, but I never seen it being an issue with other comparable products.

This installation guide has some good information in regards to proper procedures.

https://azek.com/docs/installation/AZEK_TM_Install_Guide.pdf

As to expansion, I believe Azek says for properly fastened material to allow for 1/8 in over 18 ft. In my personal experience, I think this amount is about half what it should be...especially if exposed to direct sunlight. Properly fastened material is a key factor in installation. And IMO, the more fasteners the better., and the beefier the better. We use only SS screws, I've seen materials installed with trim nails show great movement with forces that will actually bend the wire shafts...and having removed some trim where they were used showed pieces of the back of the material actually "blown out". Contrary to what some say, fasteners should be placed within 2 inches of any joints. These are the places you really want to limit movement.

Realize my opinions and comments are based on my perosanll experiance and the material being sanded and painted over filled holes. Reasons for doing so, I explain my composite home thread. YMMV

Having taken another look at the picture of your shed, unless you are planning for more framing...I'm not sure a composite material like Azek would be a good choice for your application. These material really need a solid backer material to maintain rigidity. Spanning large open distances with it is not something I would suggest.

Again...JMO.

 

[Platonic Solid]

CTyankee - Thank you for the link! That's much more detailed than the Veranda material literature. It is my intention to install additional framing to support the PVC sheet. I didn't think I'd need to put an additional backer on top of the framing if I use studs at 16" OC or less. Looking at the Azek site (link) and the instructions you linked to, it clearly states: "3/8” and 1/2” AZEK Sheet product is not intended to be ripped into trim pieces. These profiles must be glued to a substrate and mechanically fastened." They do not make any mention of backing requirements for their thicker 3/4, 1, & 1.5" large sheet offering.

 

[Jeff Ivers]

I just read through this thread. I have experience using the PVC as trim and have noted it does not have much structural strength. On the garage you are raising, I don't see any type of diagonal bracing at the corners. Use of plywood sheathing at the corners is sometimes done as an alternate to diagonal bracing. When I have used the PVC, I have predrilled and used screws.

 

[Platonic Solid]

Jeff Ivers - The corner bracing was removed along with what little remained of the sill. That will be replaced when I make a knee wall. It wouldn't take much to add plywood sheathing to the knee wall at the same time.

 

[tcianci]

I know the whole thread is about PVC but have you considered wonderboard or other cement tile backer panel. It's actually spec'd for mobile home skirting, it's dirt cheap and I have examples of it in use for over 25 years and still intact. One trick I came up with was to make a stucco of thin set tile mortar and sand and tape the seams and corners with tile backer joint tape and stucco the job. It looks like poured concrete.

 

[6768rogues]

PVC doesn't stay good looking if you run a string trimmer along it. Plan to have something other than grass up to your PVC.