How To Fasten PVC Trim Correctly

As a mod­ern, inno­v­a­tive alter­na­tive to wood trim, PVC trim is boom­ing. When installed and fas­tened cor­rect­ly, PVC trim can be cut, shaped and just as aes­thet­i­cal­ly pleas­ing as wood trim — with­out all of the dis­ad­van­tages. To set you up for suc­cess, we’ve put togeth­er a guide on how to fas­ten PVC trim to ensure your next project goes smoothly. 

By the end of this guide, you’ll know how to choose the best screws for it and how to fas­ten PVC trim boards secure­ly with a smooth instal­la­tion process. 

What Is PVC Trim?

Polyvinyl chlo­ride (PVC) is one of the most pop­u­lar forms of syn­thet­ic plas­tic poly­mers. It’s used as sid­ing for dec­o­ra­tive pur­pos­es, inte­ri­or pan­el­ing and base­boards, sheets, pipes, mold­ings and many oth­er applications. 

It is often viewed as a low-main­te­nance alter­na­tive for wood build­ing mate­ri­als. PVC trim boards specif­i­cal­ly are often used for appli­ca­tions such as sof­fit, fas­cia, rake boards, win­dow and door sur­rounds, columns and much more. 

PVC trim won’t trim or crack, won’t absorb mois­ture or rot, is pest-resis­tant and can with­stand the ele­ments — all increas­ing the material’s longevi­ty. In addi­tion, it’s a much more afford­able option com­pared to oth­er trim materials.

Fastening PVC Trim Correctly

Before you start the instal­la­tion, load up your kit with the right tools and mate­ri­als. Make sure you’re using high-qual­i­ty screws that will not suc­cumb to break­age. Use a screw sys­tem that is hard to strip out and has a high lev­el of hold­ing pow­er, espe­cial­ly when using it for larg­er trim boards.

When start­ing the instal­la­tion, secure your fas­ten­ing sys­tem. This ensures the trim boards will not move when the out­side tem­per­a­ture fluc­tu­ates with the chang­ing sea­sons. Just as if you were cut­ting wood, your tools should be sim­i­lar, exclud­ing the fasteners.

We rec­om­mend only using car­bide-tipped blades, but com­bi­na­tion saw blades will work, too. If you use plain steel blades, they’ll dull quick­ly. If you’re cut­ting your PVC trim on-site and not using fac­to­ry edges, we sug­gest you plan your project around the idea that your cut edges will be hid­den since it makes for a clean­er fin­ish. If there are any extra rough edges, you can sand it down with an orbital sander armed with 100-grit paper. A belt sander may melt the PVC as it is plas­tic, so be careful.

Just like with wood, cre­ate over­lap­ping 45-degree joints in areas where the ends of trim meet. Cut the first piece of trim to fall just past the cen­ter of the stud so the over­lap­ping piece can be secure­ly fas­tened to the stud cen­ter. Apply cement to both trim pieces before you ful­ly secure them to the wall.

If you’re installing trim in tem­per­a­tures that hit high­er than 80 degrees, you can fit joints tight­ly. If it gets cold where you’re installing, leave a gap for poten­tial expan­sion and con­trac­tion. Between 60 and 80 degrees, the stan­dard guide­line is a 1÷16” gap for every 18 ft. of length. Below 60 degrees, you should leave a ⅛” gap. Read the fine print of your man­u­fac­tur­er man­u­al to ensure the best accu­ra­cy in your gaps. You can seal the gap with paintable acrylic or polyurethane caulk.

From there, you can begin the fas­ten­ing process. Select the right screws, which we’ll detail in the next sec­tion. Fas­ten­ing well with the right screws helps with expan­sion and con­trac­tion. Make sure you fas­ten to fram­ing, nev­er just into the sheath­ing. Select fas­ten­er lengths that will be able to pen­e­trate the fram­ing by at least 1 ½”. You should place fas­ten­ers approx­i­mate­ly every 16” at both edges of the trim, with spac­ing ½” from the edges. If your trim is 10” or wider, add one more fas­ten­er in the mid­dle. For 16” wide trim, you should uti­lize four screws every 16”. 

Best Screws for PVC Trim

The best screws for PVC trim come from Cor­tex. They come in a kit that includes a bit, plugs and screws. All you do is drill the screw through the trim. Once the desired depth is reached, the bit will com­plete­ly stop the screw. Set the drill down, tap the plug in the hole, and your project is complete!

Cortex Hidden Fastening System for PVC

The Cor­tex Hid­den Fas­ten­ing Sys­tem for PVC is one of the eas­i­est ways to hide trim fas­ten­ers in PVC.

The TORX® ttap® Dri­ve Sys­tem elim­i­nates the risk of strip­ping out, and the fas­ten­er can be removed eas­i­ly. This sys­tem comes with a sta­bil­i­ty but­ton to ensure your fas­ten­er stays straight through­out the entire instal­la­tion to ensure a prop­er hold. The stronger set­ting tool is great for con­trac­tor use, as the stronger bit mate­r­i­al and indus­try-grade felt allow a 350 fas­ten­er instal­la­tion with a sin­gle Con­text Set­ting Tool. 

The short­er and faster trim screw allows instal­la­tion to be a breeze. The 2” fas­ten­ers allow for pow­er­ful holds and ver­sa­tile instal­la­tions for deck fas­cia and exte­ri­or base­board appli­ca­tions. Because of the dual thread design, the fas­ten­er spins 50% faster, speed­ing up the instal­la­tion process. 

The Collated Cortex Hidden Fastening System for PVC 

Like the pre­vi­ous PVC fas­ten­ing sys­tem, the Col­lat­ed Cor­tex Hid­den Fas­ten­ing Sys­tem is great for short­en­ing projects and sav­ing on labor costs.

The fas­ten­ers are avail­able in 2” and 2 ¾” options, both pro­vid­ing supe­ri­or strength and ver­sa­til­i­ty for appli­ca­tions. This sys­tem also has a dual thread design, so the fas­ten­er spins 50% faster than com­pet­i­tive screws, allow­ing instal­la­tion times to be quick­er and eas­i­er. The plugs for the sys­tems also come on a col­lat­ed strip, allow­ing for less han­dling and sav­ing time for work­ers on the job site. 

How FastenMaster Can Help

Through our vast prod­uct offer­ings, you can find the right fas­ten­er for any type of project, regard­less of the mate­r­i­al. Whether you’re work­ing with PVC trim, wood or steel deck fram­ing, we’ve got you covered.

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