DIY Home Improvement Forum banner

Furring Strips and insulation

7K views 8 replies 3 participants last post by  Gary in WA 
#1 ·
I am currently renovating my home's bathroom and hallway which is on the second story. The ceiling joist that separate the unfinished attic from the living space are exposed as well as the studs on all walls. The studs and joist are uneven, as the home is quite old. I was going to solve this problem by adding parallel and perpendicular furring strips and leveling them out with shims as needed, but then came the question in regards to the insulation I will be installing. I have read that furring strips can actually reduce the r rating on the insulation? Does a 3/4" gap between the Sheetrock and faced insulation bats cause any adverse affects that I should be worried about? I know furring is a common practice to solve uneven framing in older homes, so I was wondering if anybody has encountered this problem, I believe it's referred to as a thermal short??
 
#2 ·
Insulation is a better insulator than air in this case.

How about a picture of the walls now that they are opened up?

Where is the home? Is the bathroom vented properly and are you controlling moisture accumulation? What type of tile system is going up as that will dictate wall design (i.e. avoidance of a vapor trap) as well.
 
#3 ·
No the bathroom was not vented correctly, that problem is being addressed with new fan, and vent kit. The attic has no ventilation either, so I Will be installing a mechanical venting system as well And possibly a fixed dehumidifier . This is an old house and the area of it I am working on "currently" was extended in 1940, so allot of the framing is attached to the old roof line that was hiding behind the now exposed cavity. The framing in the walls are not 16oc not even 24... It's like they just threw in studs to attach the lath too where ever they saw fit.....very bizarre.... so all of that needs to be changed. I have studs that protrude out much further than the others, it's a mess....the joist seem to look good, except for the water damage that took out a few sections, that's been fixed which was the initial cause of concern....that leak was a whole other story.....on top of that there was an access panel, over the "tub/shower" which by the way the existing fan vented directly into ...the attic, which had an access panel ....which was recessed and was covered by a piece of ply over a shower?!? that when uncovered was riddled with mold before you even opened the door to the attic. The bathroom itself was wrapped in 3/4 " ply around all interior walls and ceiling, like a backer board, causing this roof leak to go undetected for decades and the framing just deteriorating between this sauna of a cavity....the subfloor was built up 2 1/2" over the years by laying 3/4 ply over ply and adding tile....finally after the hours dealing with the ply on walls and ceiling, I got down to the original sub which surprisingly managed to stay in good shape despite the layers of rotted ply that laid on top of it....the wiring "bx" had open junction boxes, and the insulated wires had lost all of its insulation leaving them completely exposed , this was packed with celious blown in insulation, an absolute God sent we didn't go up in flames, and the armored portion of the cable was rusting, all over that particular circuit, so that had to be pulled and new romex ran....and once up in the attic And moving insulation around to get to the wiring... realized the rock wool had begun to fail everywhere and moisture was trapped in it and being absorbed into the drywall, which was molding and failing because of it....so I just pulled out the crow bar and took it down as well...so now I have the hallway and bath down to studs, and removed all the old rock wool to find the termites have been having there way with the exterior sheathing and studs which I'll be spraying down tomorrow to iraticate ....I mean at this point it's a total system reboot, it has to be overhauled, and I am working on a tight budget....and it's all me, No crew no help, did renovations in Cali for years, had a good crew, and you get spoiled, but this is the dragon that's got me sharpening up my skill set...so turning to the forums and the net when I got a question, and I appreciate the response !! Thank you!!
 
#4 ·
Welcome to the forum!

A totally dead air space is fine, up to R-4. Problem with one right next to the drywall/fibrous insulation is convective looping robbing your heat and air movement IN your low-density fibrous insulation robbing R-value; pp. 45-47; http://www.buildingscienceconsultin...010-03-10_When_R-Value_Doesn t_Measure_Up.pdf

They built houses with green lumber and roughly milled, allowing the plaster to vary +1/4" for a smooth wall/ceiling. Add rigid foam board (w. ignition barrier if required) on attic side of stud walls, or inside; some XPS.
"so turning to the forums and the net when I got a question,"--- only need this forum! Lol...

Gary
 
#5 ·
Gary thank you, I'll go over this in the AM need to digest it, but apparently I am in a zone four my attic insulation is suppose to be r-38 and they are selling r30 at lowes as standard ?? So I am frustrated ...I think I have to drop the furring idea for the walls, maybe for ceiling it sounds like?? But thank you!! I'll try to shoot some images over
 
#7 ·
If you furr down the ceiling to level it, add cellulose after drywall OR you will get convective looping in the R-30 or R-38 (both are low density- less than 1 pound weight per cubic foot) + the air space= perfect to start/maintain looping (24/7) of your heating dollars; http://www.diychatroom.com/f98/biggest-loser-fiberglass-insulation-90438/

If you decide on the FG batt, at least cover them on attic side with some housewrap, to prevent wind-washing/convective looping in the low-density insulation.

The rigid foam was for wall- either side though optimum on attic side (requires an ignition barrier per fire code, check local AHJ..

Gary
 
#9 ·
Add some housewrap over the (air-permeable) Roxul to stop the attic currents/convective loops from robbing you of heating dollars spent.

Gary
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top