Ever heard of it? If you’re a contractor, of course you have. If you’re a do-it-yourselfer, maybe not. If you haven’t heard of T1-11 siding I wanted to give you a brief introduction and tell you why you might want to use it on a project.
T1-11 type siding generally comes in 2 different forms. One is based on Oriented Strand Board (OSB) and the other is plywood based. You can get 4×8 sheets of either type at the local lumber store. The OSB type has a wood grain look embossed on the exterior of the sheet, whereas the plywood based T1-11 has a rough- sawn wood appearance on the exterior. Both types have vertical grooves 8 inches on center.
The plywood type T1-11 is what I used so that’s what I’ll be talking about in this video. I like it because it has 5 plies and is about 5/8 inches thick. The edges of the sheet are half lap joints so that when it is installed you can’t see the seams between sheets.
T1-11 is used on all types of residential and commercial buildings. Everything from sheds, to houses, to restaurants and small office buildings. I used it to re-side a house recently and wanted to show you how it looks. Since so many houses have vinyl siding on them, T1-11 gives a unique look. Also, at for a 4×8 sheet the price is reasonable.
Before I show you my project, I wanted to share some things I did to the T1-11 before attaching it to the building. Since this is a wood product I wanted to paint all sides before installing it. This may seem like overkill, but I wanted to protect against future water damage. Just think of this as insurance. I also painted any edges or cuts that I made.
A good paint for the finish coat is Valspar Duramax available at Lowe’s. It’s a paint and primer in one and is great for the exterior side of the siding but it is a bit expensive. With that in mind you probably want to buy and use a regular primer for the back side of the T1-11 sheet. Regular primer will still be over a gallon but will save you some money when compared to the expense of the Valspar Duramax.
Another thing you will need is caulking. The one I like is called OSI Quad Advanced Formula Sealant for windows, doors, and siding. It is paintable but comes in various colors and is flexible even in very cold temperatures and costs about per tube.
Now, here’s some footage of my project. You can see we set up some saw horses and painted everything before we installed it. We painted the back of the siding with regular primer and we painted the front with Valspar Duramax.
To make things easier and safer, we rented some scaffolding from Home Depot. Other than that we just worked across the house, one 4 by 8 sheet at a time. We removed the old rigid insulation and replaced it with 2 inch rigid insulation under the siding and taped the joints. After installing the trim, we caulked the top but left the bottom open so moisture wouldn’t be trapped.
Well, that’s it for now and I hope you enjoyed this intro to T1-11 siding. Thanks for watching.