What is T1-11 plywood siding? Is it worth using for a home or outbuilding? This wood-based siding product isn’t as popular as it used to be, but it still has quite a few good uses. Here’s your complete guide to choosing and using T1-11 siding.
T1-11 Siding Basics
You’ve probably seen T1-11 siding at least a few times in your life. This handy forestry product was very popular throughout the 1960s, 70s, and 80s, but fell out of favor as aluminum, vinyl, and composite siding gained popularity. Luckily, manufacturers still make good quality T1-11 siding. It might not be your first choice for building a home, but it could be ideal for finishing up a shed, chicken coop, or other outbuilding in an inexpensive, attractive way.
There are two plywood siding panel T1-11 grades: Plywood and OSB. The OSB version is usually a bit cheaper than the plywood, but there’s a downside: OSB doesn’t normally last as long, it’s easier to damage, and it can’t be finished in as many was as plywood T1-11 siding. If you have the option, choose pressure treated T-1-11 plywood siding. It’s more expensive than other versions, but it’ll last longer.
T1-11 Plywood Siding Specifications
Most T1-11 siding products come in sheets measuring 48×96 inches or 48×120 inches. Just like plywood, T1-11 siding comes in a variety of thicknesses. The most common T1-11 siding sheet thicknesses are 3/8”, 5/8”, and 3/4”.
The grooves in T1-11 siding may be four or eight inches apart. Some companies also offer a pleasing reverse board and batten design. There’s no structural difference here; the main factor is aesthetics, and this decision is a mere matter of personal preference.
Depending on the manufacturer and supplier, you may find T1-11 siding in a smooth finish, or in a rough, more rustic finish. Both types are acceptable, but the rough, rugged surface does provide a more rustic, natural appearance.
Plywood T1-11 siding can be stained, or it can be primed and painted. The choice is yours! If you opt for OSB T1-11 siding, you will need to prime and paint it with an opaque finish such as exterior grade paint. Because the OSB strands show through the surface, this type of T1-11 siding is not suitable for stain finishes.
How to Install T1-11
Before you get started with T1-11 siding installation, note that this type of siding should never be installed in contact with the ground. The edges are absorbent, and contact with moisture will lead to separation. When this happens, T1-11 siding becomes susceptible to mold, meaning it will need to be replaced long before its expected lifespan has come to an end.
All types of T1-11 siding have outer edges with 3/8-inch wide lips designed to overlap the piece that was installed previously. The edges should be positioned over a stud and nailed into place together rather than separately. Be sure to measure carefully and double check any cuts beforehand. If you make a mistake and have to remove a nail or two, you’re likely to damage the siding.
Use a circular saw to cut T1-11 to fit around windows and doors. Allow a ½-inch expansion gap.
Depending on your location and the type of project you’re working on, you may be able to use T1-11 siding alone, without any other sheathing beneath it. This is a very economical way to go, but keep in mind, your building will be stronger if you use another product underneath the T1-11. Again, this is a choice that’s completely up to you. If you’re more interested in prolonging your siding’s lifespan, treat it like any other siding product by placing it over sheathing and installing a layer of house wrap or tar paper underneath.
As with any project, you will want to apply lumber trim pieces to the corners and around any windows, and you’ll want to apply Z-flashing to any upper joints to prevent water from leaking under the top edges of your sheets.
It’s a good idea to paint or stain the edges and joints of T1-11 siding before you install it. This way, there’s nowhere for moisture to accumulate and cause damage. It’s an extra step and you’ll need to allow for a bit of drying time, but your siding will thank you by offering greater longevity.
After installation, finish T1-11 siding with your choice of exterior stain, or go with a primer and paint combination that suits your budget as well as your sense of taste.
It’s worth noting that T1-11 siding is fairly easy to install. Many guides recommend hiring a professional to do it for you, but considering that part of this product’s appeal is its inexpensive price tag, you may want to spend some time planning your project, plan carefully, and then hang the siding yourself. It’s a fairly forgiving product – you simply need to ensure that you follow guidelines for overlapping edges and ensuring that all your lines are straight.
How to Maintain T1-11 Siding
There’s a common misperception that T1-11 siding always fails, eventually. This doesn’t have to be true. Just like other forestry products, T1-11 benefits from plenty of TLC. Protective finishes go a long way. As with any other wood siding, T1-11 requires a fresh coat of stain every three to five years. Do not skimp on the finish, and consider applying new stain before the wood starts to look like it’s showing some wear.
If you have painted T1-11 siding, you’ll find that the look is less natural, but the upkeep is a bit more forgiving. In general, T1-11 siding that has been painted needs to be refinished every ten to fifteen years or so, depending on factors such as weather conditions and the type of paint that was used in the original project.
Is T1-11 Siding Worth It?
If you’re looking for a fairly attractive product that you can install yourself at a lower price than many other popular siding types, then go for it. T1-11 siding has pros and cons just like any other building material. When properly installed and maintained, it offers an attractive appearance and provides your building with protection from the elements.