Replacing siding (and TenTest or not?)

5/11/2011 at 12:36:50 PM

Hi Randy,

You have several different things going on it seems. Ultimately, you need to decide what it is you're really after? If you want to make the outside look nice, you could simply invest in a really good paint job and replace only the boards that are cupping or cracked. If you want to go for the energy efficiency aspect, then obviously there is a lot you can do. The trick is going to be figuring out what your real target is otherwise you can blow your budget pretty quickly. My answers to your questions are as follows:

1) there is nothing wrong with ten test. Without getting into a whole building science debate, ten test has more admirable properties than many building products today. My motto is, if it ain't broke don't fix it! You won't know the real condition of the ten test until you start stripping off the old siding. If it is in decent shape, leave it alone. Where there are damaged areas, you can make repairs using OSB/plywood and roofing paper. But again - this all depends on what you're trying to acomplish?

2) Recommendations on wood or composite products - some others might be better able to jump in on their preference. I suggest if you're going the full replacement route, choose a product based on it's long-term durability and maintenance free qualities. I assume the only reason you're doing away with the existing wood siding is because it's been difficult to keep up with painting, etc.

3) Siding over the wood - you can do it, sure. There are plenty of examples of Victorian homes that have been wrecked by slapping aluminum or vinyl siding over the top of the preexisiting cladding. Again, I question what your motives are for covering the wood? An intensive paint job might work out to be less than residing with vinyl - but it will require on-going care.

4) In terms of energy efficiency, there is a ton of stuff that can be done if you're going to the trouble of stripping the exterior of the house. My caution in using some exterior styrofoam products is they *can* act as a vapour barrier. Check the manufacturer's specs to be sure. You want a product that "breathes" on the outside like tar paper, ten test or Typar/Tyvek. It's important to allow any trapped moisture in the walls to escape. And remember to install from the bottom up to the roof, overlapping joints 6"-8".

~ Dave

5/11/2011 at 5:28:19 PM

Dave, thanks for the reply. The existing siding is cupping in quite a few places so I'd have to replace quite a bit - 20% at least so my aim is to replace it with something that doesn't need much maintenance and while doing that, add some R value, seal up the envelope a bit. So the aim, the answer to your question, is both long term maintenance and insulation.

5/12/2011 at 9:39:19 AM

Hi again Randy,

In that case, I think to achieve your two primary goals of increasing R-value and air sealing, adding an exterior insulation product would be the simplest all-in-one solution. There's really no need to remove the tentest if you don't want to (again depending on condition. If there is water damage or mould or other nasties, of course take it off). You can apply the exterior insulation over top and then new cladding over that. The exterior insulation will provide a good air-barrier if sealed properly. The trouble you're going to have is extending your door/window jambs and sills the extra 1-2" to make them weather tight. It can be done, but it's fiddly work. Good luck with it!

~ Dave