View Full Version : Should I insulate attic first or install vinyl siding

01-22-2009, 12:07 PM
Hi folks,

Single gal homeowner here looking for advise:

ok...I have a small Cape Cod style house in the New England area with wood shingles. The shingles are badly worn, cracked and just too costly to replace so I will have to go with vinyl siding.

Also, my attic is unfinished, with that old pink cotton looking insulation that is falling down. So, I will be needing new insulation.....not sure what kind to get, something non-chemical and environmentally friendly is preferred.

So.....my question is....should I insulate first or have the house sided first, or does it really matter.

01-22-2009, 12:48 PM
Insulating the attic could be done now & will save you on heating costs. Are you going to put the siding up or hire someone? If you are hiring then now would be a good time to start getting quotes
You can save $$ if you (or friends) can rip the old stuff off & dispose of it. Just make sure whoever is going to re-side is ready to go right afterwards

Do you have soffit venting or vents at the gables (either end)? Is the insulation on the attic floor or up against the rafters

01-23-2009, 04:42 AM
IT depends on whether you want to save money on your heating bill, or want the house to look pretty.

01-23-2009, 06:39 AM
Thanks Scuba Dave for your reply.....my heating bill (gas, forced hot air) is very high so yes, I do want to save on heating costs...so now sounds like the right time.

Re: siding the house, I will have to hire someone...not sure where to start...I'd like to go with a reputable company if possible, maybe Lowes, or Home Depot just in case I have problems. As for ripping off the old stuff...there are wood shingles on the house...I thought you leave those on and side over them? Don't know about soffit vents.

The insulation is only in the rafters and is falling down....the floor does not have insulation.

To HJ: thanks for your reply as well....yes I do need to save on my heating bills.:)

01-23-2009, 07:02 AM
You are right - they can side over the shingles - that's what they did to my house. As long as there is only 1 layer of shingles you should be OK. My vinyl siding is old so most has been removed & I am going with wood shingles & cement board as siding

Is there a floor you can walk on? Loose plywood?
I would insulate the floor 1st
At my friends we took all the old insulation & added that to one area that needed it (floor). We then added floor insulation. We then insulation the rafters using R19. So the heat had to go thru R30 then R19 to get "out". We only used R19 to allow the roof deck to be vented - he had a ridge vent. So the roof deck was vented & the attic was insulated. We added plywood to the floor & sheetrock on the rafters. The attic stayed fairly warm depending upon the outside Temp

If you have 2-10's for joists on the floor you could use R30
If you have 2x6's many people advise to raise the "floor" up to add more insulation. I will have R30 to R38 in all of my new insulation areas, a small older area has R25.
So the floor would be an "easy" fix depending upon your joist size
You want the "faced" side of the insulation facing down towards the heated side of the house on the floor

I'm working on adding insulation to my MIL's attic - only R19
Her 2nd floor is not used - so the heat is kept at about 50
But the heat is going thru the ceiling

01-23-2009, 01:23 PM
Thanks again Scuba Dave.....you sound live a diver....great diving in Rockport, MA, beautiful part of New England.

My attic is quite large, and yes it has the original wood floors down, it still remains in the original condition from when it was built, just fiberglass insulation in the rafters which is old and coming down as stated earlier and not covering every wall.

I will show your email to my union carpenter since I am not familiar with some of your terms...but greatly appreciate your replies. Do you like the foam insulation?

01-23-2009, 02:00 PM
Just a quick clarification - you mentioned that you'd like to use a reputable company, then mentioned Lowe's or Home Depot? Lowes & HD sub-contract their jobs to contractors, at prices than guarantee shoddy work.

Find an independant contractor that's been in business for awhile - Take the time to meet with a few, don't hire the first one you meet. Ask for references, and check them. Compare warranties. Quiz them on your options, see what they recommend, check their answers here...

01-24-2009, 07:06 PM

Just a quick question. Once the heat from your top floor living space got into the attic, why do you care if it left the attic?

Is the thinking that the warmer the attic stayed, the less heat would leave the top floor? Wouldn't there be a problem with condensation on the rafters in that case?

If warm attic air was in constant contact with cold rafters, it would create condensation which can lead to rot and mold. My thinking would be that any warm air that made it's way through the attic floor insulation would want to be immediately vented out of the attic.

I don't know. You tell me.

01-24-2009, 07:43 PM
An attic is an attic in a name only in this case
Many people dormer the back of a Cape house to add room
Deck venting is installed (rafter vents), then insulation, then sheetrock. Soffit vents & ridge vent allows the roof deck to be vented. The attic is then living space.
So the warm attic air is prevented from contact with the roof decking


My Cape is dormered & has this method. It is not heated at this point or 100% finished. It very rarely goes under 45 up there except in a stretch of cold weather. The floor of the attic was insulated by a prior owner with R25. It was actually rented out by the prior owner as an Apt - BEFORE it was dormered (very little head room) !! No vents, no rafter vents, no ridge vent, no rot. Mixture of R7, R19 & R25 on the roof rafters

01-26-2009, 07:45 AM
Many thanks Frenchie for your suggestion about independent contractors. I will make it a point do that. Thanks again Scuba and HJ also for your replies....this website is great!:)