Vinyl Siding Insulation

[SLOBuds]

I plan to have vinyl siding installed over a house that was built in the mid-1980s. My understanding from friends is that insulation can be applied between siding and old wall. So in my case the exterior is T1-11, which then would have a foam insulation board installed onto it, and then the vinyl siding would be on the outside. Possibly a vapor barrior somewhere in the mix.

I would like to add a significant amount of insulation to my walls.

Is it possible to add thick foam insulation boards between the T1-11 and siding? I am thinking in the order of 4"-6".

What are the issues of going this direction, if possible?

Thanks,
Martin

[Bird]

I have a 21' x 25' "shop" building connected to the back of my house via 12' breezeway. The house is brick veneer, built in 1991, and the front of that shop building is brick, also. However, the other 3 walls of the shop were T1-11 siding. I got 3 estimates for vinyl siding to go over the T1-11 and all said the "usual" thing is to put 1/2" styrofoam on, then the viny siding, or if you don't really need more insulation (and I did not), they can use 1/4" styrofoam which is a little cheaper. However, I decided to go with Tyvek for the vapor barrier, then Alcoa Structure vinyl siding with the foam bonded onto each piece of vinyl. I'm very happy with it, but it was only done in July. I'll attach a picture. I don't think you can go with 4" to 6" insulation like you mentioned because the nails have to go through the insulation into the existing siding, or the studs, and they are in slots instead of round holes in the vinyl so it can contract and expand slightly with temperature changes.

[Pat]

On my new hoiuse I used the for fit foam insulation that is an exact fit to the siding and tends to insulate plus reinforce the vinyl and it sure feels better to the touch.

Adding rigid foam over the old and then vinyl ovver than is OK but at some thickness you will create a little problem with getting a neat fit around openings. In my book, more insulation is worth most problems you would encounter. About that house wrap or vapor retarder... don'tcha think the rigid foam pretty much eliminates a need for it?

I'm all for MORE INSULATION!!!

Pat [img]/forums/images/icons/smile.gif[/img] [img]/forums/images/icons/smile.gif[/img]

[Bird]

</font><blockquote><font class="small">In reply to:</font><hr />
About that house wrap or vapor retarder... don'tcha think the rigid foam pretty much eliminates a need for it?

[/ QUOTE ]

Actually I do think so, but some seem to think it's a good idea, so I decided to not take any chances. [img]/forums/images/icons/tongue.gif[/img]

[SLOBuds]

Well, there's been no fence-sitting about my vinyl siding questions. Hare are a couple of message strings in case anyone is interested.

Tractor By Net Vinyl Siding String

Taunton Fine Homebuilding Vinyl Siding String

I first decided to turn away from vinyl because of what I read about off-gassing, and other things. Now I have turned back because I believe the concerns are over-stated and the product's benefits outweigh its deficiencies.

Thanks,
Martin