New Clapboards Over Existing T1-11 Siding ?

[Robert11]

Hello:

Moved into a 30 yr old house that has the vertical T1-11 (I'm told that is what it is called) for the outside surface. Several pieces are damage, as well as some of the ends having soaked up water over the years, and should be replaced.

Guess there are several ways to go.

I can have vinyl siding applied.

Another possibility that I was wondering about is whether it is possible, or practical, to have the more normal/conventional horizontal wood board type of siding applied. Not sure what the correct term is (clapboards ?)

Any thoughts on this, particularly regarding whether it can, or should, be applied directly over the existing T1-11 ?

Would like to consider doing it without stripping the whole house. Also, I imagine it would provide a bit more insulation, and be a lot simpler and inexpensive to do it without removing the old T1-11 first.

Thoughts on ?

Thanks, Bob

[No]

If it were me... I would remove any rotted sections of the T1-11. Then consider new siding. t111 has problems, as you can see. If you do not strip off the old t111 then your new siding may come out too far around your windows. This may look ugly. (better than t111? hmmm). I really like the look of horizontal wood clapboards. My old house had them. If you are going painted then there is a cement based product that looks a lot better than vinyl. See

When installing this, if the t111 is right to the studs, then it can remain. (Except for rotted areas, that should be fixed) I would cover the entire house it in tyvek or some other air infiltration barrier first. then install the siding. Same for vinyl but the cement boards will look a lot better.

For a natural wood, this is what I did on my old house. Horizontal beveled, Grade A (Not the highest grade, a few small knots), western red cedar, treated with Sikkens 123plus three coat process. I then every couple of years freshened up the treatment with a quick brush on of the 23plus as per the manufactures instructions. This could also have been painted. See

for some good info on cedar siding.

I think Vinyl is ugliest of all, its also probably cheapest. The advantage is its truly zero maintenance. I have it on the back of my new house. Yuck.

[William W. Plummer]

Have the old T 1-11 removed, exposing the plywood siding. Then have Tyvek wrapper applied to cut heat loss by air flow. Then, styrofoam insulation goes on. Finally, the finish siding of your choice. On a Cape style house, I like cedar shakes. Real wood clapboards are good also, but require paining. Vinyl siding looks too uniform for my taste and it can break. Aluminum dents.

[L. M. Rappaport]

On Thu, 26 May 2005 08:04:54 -0400, "Robert11" wrote (with possible editing):

T111 was never meant to be siding, it is considered sheathing, like the normal 5/8" CDX which it replaces, although the grooves make it somewhat better looking. The idea was that you could apply sheathing when built and apply siding later.

You should replace the damaged T111 before doing anything. That is the only barrier between the inside and the outside!

Normal construction places sheathing over the studs and then the siding is applied over that.

You might want to provide an extra layer of insulation first.

That would be fine. Normally, you would apply a layer of Typar first.

No problem, that is the way it was originally designed to be used.