When and Where to Use Drywall Accessories Made for Movement

When and Where Made for Movement deflection bead hero

Many of us just accept that ugly cracks in drywall due to movement are bound to happen sooner or later — but it doesn’t have to be that way. One of the key reasons the folks here at Trim-Tex are big believers in the power of vinyl drywall accessories is the material’s ability to move. We’re able to manufacture beads where rigid vinyl and flexible vinyl are fused together to create something perfectly engineered to handle structural movement.

We’ve made several of these unique sorts of solutions; some drywall finishers have loved for decades and some are more recent innovations. But we often get asked: what’s the difference between them? Here’s when and where to use drywall accessories made for movement, and which Trim-Tex bead you should choose for which job.

Expansion and control joints

Building codes require that a drywall control/expansion joint be placed every 30 feet along uninterrupted wall or ceiling partitions. These flexible joints basically provide a form of relief for these long drywall runs, as too much tension causes cracks, or worse. And don’t assume we’re just talking about commercial construction here — there are many situations where a control joint or two would be critical in residential spaces too, especially in big, open areas like garages.

When and Where Made for Movement Expansion Loop 2

Zinc beads for control joints have been around for ages, sure, but most drywall pros already know: if it moves, it’s better when it’s vinyl. Trim-Tex’s 093V Expansion bead is used on everything from custom homes to the highest high rises around the world for good reasons: It’s easy to install, our famous tear-off strips protect the middle “V” section of the bead from mud spilling into it, and it will keep your expansion joint elastic for years to come.

Additional options include: a Hideaway Expansion for a more subtle look. Then, like the Fire Bead and Deflection Bead, there’s the Fire Rated 093V Expansion for the same bead in a fire rated form.

When and Where Made for Movement magic corner

Vaulted ceilings, cathedral ceilings and other off-angle inside corners

Off-angle inside corners — like the kinds you’ll see running along vaulted or cathedral ceilings — are some of the most common locations of cracks appearing in residential properties. That’s because these joints are bridging the gap between the ceiling and the walls, both of which are going to move slightly in their own directions, at their own paces, as the temperature and/or humidity levels around them shift. So, if a highly rigid bead or even just paper tape is installed here, you can expect cracking to occur sooner or later as the walls and ceilings pull away from each other.

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This is where a vinyl bead like Magic Corner can be, well, magical. It comes equipped with rigid vinyl mud legs on either side that will ensure a gorgeous finish, and its flexible inner flange accommodates up to 3/8” movement to protect against cracking.

Additional options include: though it may not be quite as movement-friendly as Magic Corner, we always recommend the paper-covered Fast Edge® Roll for off-angle inside corners that install quickly and look great with perfectly straight lines.

When and Where Made for Movement deflection bead

Head-of-wall joints

In commercial construction, outfitting head-of-wall joints for movement has been a source of frustration for ages. Especially when your multi-story building starts getting into the high-rise territory, it becomes a matter of when, not if, building deflection (where the structure changes shape slightly under a heavy load and gravitational force) causes huge cracks in your finish wherever walls meet ceilings. Those cracks are unsightly at best and dangerous at worst — your drywall is a fire-protective shield, and damage makes it vulnerable.

Years ago, you would usually just defend from head-of-wall deflection with some kind of caulk. But caulk is notorious for hardening and shrinking back over time, and your once-flexible wall joint is now completely inflexible.

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Vinyl drywall accessories, on the other hand, can stay flexible forever — that’s why so many commercial contractors now use Trim-Tex’s Deflection Bead in these areas. Deflection Bead has a flexible bubble gasket at its apex that compresses against the ceiling when installed; it flexes with the structure as it moves (up to 7⁄16” of controlled movement) so cracks won’t occur here. Its rigid vinyl leg also gives you a lovely, long-lasting finish, too.

Additional options include: If you’re installing backing materials (like the compressible foam Hotrod Type-X) behind the bead, your best option would be the backless Flat Deflection Bead. And, for fire rated walls, you’ve got a few options to choose between, but the trailblazing Fire Bead is the same as our Deflection Bead with intumescent firestopping abilities.

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Truss uplift

Even more than vaulted ceilings, temperature and moisture can wreak havoc on the finish of drywall attached to truss rafters. Truss uplift is a complex topic (learn everything there is to know about truss uplift and the corner cracks it causes here) but the short version is: cold weather will cause the truss rafters to bow upward and — since the interior of the house stays at a warmer temperature than those rafters — this pulls adjoining ceilings away from any interior wall partitions, tearing any paper tape you’ve put on those joints.

When and Where Made for Movement Truss Loop 1

You can eliminate any cracks from truss uplift by pre-installing vinyl Truss Backing Angles. This allows the trusses to move independently from the interior walls of the house during the colder months — the drywall can just flex slowly as the rafter moves up, but the drywall along the wall/ceiling intersection stays in place.

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Movement around windows

Just like with your trusses, the reason the areas around windows move is because the temperatures on either side of the window can be vastly different. So, when you’re sealing off the gaps around your windows from cold/hot air coming in, you also have to account for some level of flexibility. This is usually done with caulk, but as discussed earlier, caulk has its issues — it’s tricky to get the dosage right, and can harden and shrink back over time.

This is another case where a little bit of flexible vinyl can go a long way. Our Super Seal Tear Away L Bead functions the same as a classic Trim-Tex Tear Away Bead that drywall folks have been using around windows, doors and more for decades, but equipped with a bubble gasket that presses against the adjoining substrates to form a perfect, permanent seal. And, more to the point, this will keep the joint flexible to account for structural movement for the long haul.

When choosing drywall accessories made for movement, make sure you're choosing high-quality materials that can flex along with the structure, as well as look great and stay durable for years to come. These movement-ready beads are just one line of products within Trim-Tex’s full array of useful drywall solutions — hit the button below to request a free catalog to check out everything we’ve got to offer.

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