I'm tearing off my nasty aluminum siding down to the original tongue-and-groove dutchlap-type wood siding. The original wood siding is generally in pretty good condition, but there are a few places where there are some holes, cracks and gaps--mostly around the area where someone once put new windows in. I've taken those (large) windows out and framed for new, smaller windows. I patched in new sheathing to cover the old window space.

I'm going to wrap the entire house in Tyvek or another similar housewrap. How important is it to seal those cracks and gaps under the housewrap? Say I didn't do anything with them... won't the housewrap (properly applied and taped) block air infiltration through those openings? And from an insulation viewpoint, isn't the insulating benefit of sealing those openings minimal (not much better than the wood siding itself)?

Don't get me wrong... I'm not saying that I'm planning on doing nothing with these openings--I will fill them, but I want to know how diligent I need to be, considering that I'll be using a housewrap. I don't need to go to the level of filling the nail holes from the aluminum siding, do I?

Your comments and suggestions are appreciated. Please be kind to me--often when I ask these types of questions (not always in this forum) I get blasted by somebody who thinks I'm trying to cut corners or half-a$$ a project. I assure you I'm not.

Thanks,

Brian

 

Tyvek will stop wind and water but allow the house to breath. If the cracks and things are really minimal, either use cheap caulk or ignore them. For the larger gaps and holes you could use some of that spray foam. Just be very carefull when using it around doors and windows, there is a seperate product to use around those areas that expands less.

 

I would consider installing 1/2 foam over the old siding. Since it is an older home the chances are good that the walls aren't overly insulated. The foam would up the r value and cover the holes at trhe same time.
just my 2 cents.

 

Actually the walls aren't insulated at all. I had originally planned on fanfold, but scrapped that idea because the extra R1 won't make any difference as the only insulation. I will insulate all walls at a future date. Thanks for the input,

Brian

 

While you have it stripped down like that it may be worth while to have cellulose blown in before wrapping it up. Not sure where you live but our winters warrant it. We are planning to strip and reside our our "new" house (circa 1905) next spring, replacing some unloved cedar shingles with clapboards. Before the new claps go up we'll add 1/2" foam board in addition to wrapping it since the cost of heating fuel seems to only be going up and up.

 

I'm near Pittsburgh PA, so it would absolutely be worth it, but I'm only opening portions of the wall. I'll insulate what's open (from the inside), but it'll be a few years until I can get all the walls done.

Funny that you should mention heating oil--we're at less than 1/8 tank, and we just had a cold snowy weekend. I refuse to pay $2/gallon for oil, so I shut down the furnace & I'll get oil in the summer when prices come down. Last night, it was 47 degrees INSIDE the first floor of my house--we're using an electric heater to get through the cold spell.

Thanks for the input,

Brian

 

Actually, adding 4x8 foam insulation sheets doesn't seem like much, but every bit helps. Surely if you dont plan to insulate the inside of the house in the very close future. Depending on the thickness you choose, you can get up to a R3.6 for half inch sheets. That far exceeds fanfolds rating.

http://www.dow.com/styrofoam/na/iso/tuff_r.htm

That chart gives you an idea of the insulating values by thickness.

As far as heating, yes its insane, so i would try to insulate everything as good as you can. I switched to a wood pellet stove this year, oil is only used for hot water and backup.

 

Interesting. I honestly had no idea that 1/2 inch styrofoam offered that high an R-value. I'm going to look into it further.

If I use the styrofoam, can I go without the housewrap--does the styrofoam provide the same benefit?

Another question: I'm going to add a new porch roof to the front face of the house (the first face I'm residing). Can I frame overtop of the styrofoam--can the ledger sandwich the foam, or should the styrofoam trim around the porch roof after it's framed?

Thanks for the info,

Brian

 

I recommened tyvek and the foam. Each one has its own job to do.

As for the porch, figure out where the ledger board needs to go and fasten it before installing the insulation. You can fasten the ledger after the house wrap. Do not forget you will need to install flashing for the porch roof before you install any siding.

 

bmears
might go to http://www.warmair.net and see if you saved any $$$ on fuel cost therewith electric.

ED

 

My old farm house was built in the late 30's and has solid wood walls and ceilings inside and had wood 3 tier siding on the outside and no insulation. I started out going to wrap the house in tyvek and then put on 1/2 " foam board and then my masonite siding. All this was to much thickness and my masonite siding would not bump up against the window but go completely over the front of them. Resolution was to remove original siding,use vat insulation r13, wrap house in Tyvek, then my masonite siding. Most comfortable house I ever been in temperture wise.

 

I contacted Dow (who makes the styrofoam sheathing). If properly taped, the sheathing (Super Tuff-R) provides the same function as a housewrap & is accepted as a weather-resistant barrier. That's the route I've decided to go. I'm putting all new windows and doors in, so I won't have any thickness problems.

Hellrazor--thanks for the suggestion--I wouldn't have considered the styrofoam if it wasn't for your post. Thanks to everybody else that responded as well.

Brian