Old colonial, 4″ wall studs, Insulation?
Last Feb (year ago) bought a 100 year old 2 story colonial near Bangor Maine. The house has plaster walls on actual 4″ studs. It also has several rooms on the same post and tube wiring. Due to the post and tube wiring paying extra on insurance. There is no insulation in the walls.
So my project is to remove all the plaster and lathe (needs it anyway). Remove the post and tube wiring. Install new service panel and romex. The house is in L configuration. I need to keep other areas liveable while doing the renovations. Plan is to do 1 room above the other in the front of the house, then the other half. And last the kitchen / dining wing.
Question is how to insulate the 4″ wall cavity for best R-value and of course least cost (not asking alot I know). I first considered all spray foam but the cost is too high for my budget. Next idea was 1″ of spray foam with fiberglass over the top. Third choice was 3/4″ foam board with edges sealed with can foam, and fiberglass over the top. I want to seal the cavities to prevent air penetration. I know by compressing the fiberglass that you loose some r-value. But thought 3/4 board and r-13 fiberglass would get me close to r-16 in the walls. And is the least expensive as far as I can tell. Any other suggestions? Ideas?
Will be doing the work myself, with help of wife. And occasionally some family members who are in the trades. Have all of the warm season to complete the project.
Edited 2/24/2008 12:47 pm ET by benhasajeep
Replies
Are there sheathing boards beneath the clapboards or are the clapboards nailed directly to the studs?
Peach full,
easy feelin'.
Edited 2/24/2008 12:44 pm ET by rez
I don't know for sure on the whole house. But an area I put a hold in the wall in a closet looks as the walls have 1x wood planks with the clap board over it. Plus I believe they installed vinyl over everything. Maybe 1/2" sheet insul under the vinyl even.
I just did some quick figuring. For each wall cavity 4" of DIY foam is $38 (between each stud (approx r-28). 4" of rigid foam (2 layers of 2" r-10 sheet) sealed with can foam is $20 (r-20). 3/4 foam board and r-13 fiberglass is $7 (approx r-16). Prices are from local borg except spray foam which is 605 kit of tiger foam for $630.
Is it worth paying double to get an extra r-4?? Or 5x to double the r value? Maine and long heating season. Am I better off in the long run to pay the premium for foam (save in oil??)
I have not called a contractor but not sure they could price it very well since it would only be about 1,000 sqft of wall surface to spray each time. 3 to 4 trips to do 2,100 sqft house. From what I have read they are about $1 per sqft per inch. Which is the same as the DIY kits.
Once your shell is tightened up the best you can against air infiltration give attic R more attention than walls.
RiverSong's suggestion for walls is an easy DIYer as you are planning three or four separate divisions as you run at the mountain.
High Density Cellulose as in a Mooney wall, which would be valuable to you to do a search of old Breaktime posts for the education, has a proven track record.
Others have had similar questions over the years and the archives have an extensive knowledge base which will provide much insight to what you are attempting.
If you scroll up in the upper left corner of your screen there is an advanced search function
Post New
Advanced Search
which upon clicking will take you to a page of instructions directing you to previous threads dealing with whatever you type in the search bar which is found on that page.
If you type in 'roof venting', 'foam insulation', 'dense cellulose' or other keywords of the subject matter you'll get a supply of data from those old threads.
Don't give fiberglass a second thought, especially seeing the amount of labor you will be doing.
Have you demoed and renovated like this before?
Cheers
Peach full,easy feelin'.
ben...here's a link to the mooney wall
http://forums.taunton.com/tp-breaktime/messages?msg=65624.1
it is usually not a good idea to start a different thread ... pepole who are following your orignial thread get lostMike Smith Rhode Island : Design / Build / Repair / Restore
101368.1 is the extension of this thread topic.
Peach full,easy feelin'.
I have used the search function and felt my question was a little bit different than the others. During the search is when I found your not allowed to insulate around knob and tube wiring due to fire hazards.
I am not in the trades now, but was for a couple years out of high school as a carpenter (apprentice and journeyman). I have family members in every trade except maybe hvac. So I am very familiar with at least basic work in several of the trades as I would help when needed.
The roof is currently insulated as much as it can be at the moment (finished attic filled with fiberglass). Future plans call for dormers and a change in pitch. At that time I will change to a more efficient insulation system.
So my main concern at the moment is the walls. I had a hard time deciding between going from the outside vs. inside route. I chose inside as I am going to bring the house up to NEC and will have to move outlets and add switches. Walls themselves are not that bad in shape but ceilings need replaced. So the ceilings tied with having to repair / open up interior walls for electric, I chose to go from the inside.
Also because I am not in the trades I don't know what new systems or techniques that might be available. Biggest problem is if I use a contractor for work, I will have to pay a premium as it will be 3 or 4 small jobs vs. 1 large job. That would cost me more and understandiably so. So that does negate using some of the systems available.
I will be doing the outside of the house as well. But like I said I believe completing the inside first is probably the best choice. I can add more insulation on the outside when that occurs.
Air infiltration is a problem. It is bad enough it was suggested to me to do some repairs first before I have the house tested. There are several obvious areas that need work, no testing needed to reval the problem.
Thanks for the information.
Edited 2/24/2008 6:24 pm ET by benhasajeep
google on Regal Wall... and learn how to blow cellulose, covering the studs with insulweb
forget about the fiberglass
Any idea on the cost roughly? I saw this on dirty jobs but really didn't consider it.
I am aiming for diy but it may be worth it to have this for insulation and have a contractor do it. Again of course depending on price.
My suggestion for DIY:
Cut 2" foil-faced isocyanurate foam board to fit tightly between studs and foam edges for seal.
Leave 2" air gap for wiring (by the way, the old stuff is called "knob & tube"). This will create a lowE air space that will give you a "free" R-2.8.
Apply 1" foil-faced isocyanurate foam board over studs to create thermal break, and drywall over that (it will require window & door jamb extensions).
This will offer a whole-wall R-value (assuming 16" oc framing) of R-25 (R-25.7 with 24" oc). The wall cavities between framing will be R-27.3 (including everything from drywall to siding).
If you apply 3/4" strapping over the inside foam board before drywall, you can get an additional R-2.8.
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