Insulation Between Joist and Chimney
HandyPock
| Posted in Construction Techniques on
I recently repaired a ceiling above a hearth. We tried to find a roof leak and couldn’t.
I opened the wall and found that the builder had insulated between the floor joist and the cinder block chimney with “Pink” insulation. I contend that the chimney “sweated” and condensation soaked the insulation and inturn got the sheetrock wet.
I pulled the insulation and we are waiting for the next rain to check my theory. I’d appreciate any input.
Replies
I wonder how that much moisture got in such a normally dry location (the chimney cant sweat if the moisture isnt there. What is the chimney ext faced with? age? chimney most likely needs sealed. I wore out many roofers until i went to the wall with the brick institute and figured out that how they make brick is just like anything else these days, driven by profit. since then =-20 years ive sealed all chimneys and not had a problem. might not be enough to see but enough to provide that moisture. good luck
Chimney is cinder block faced with soft bricks on the outside. The Homeowners said they were not aware of any sealing of the bricks. i also suggested that they get a spring loaded cap to close off the chimney when it rains. The home is on the coast of Maine. HandyPock
does chimney have a damper? does it have flue liner? if it doesnt have a damper ( you didnt give age) then something needs to be done to improve the efficiency of the unit enyway. flue liners wont absorb enough water to caust this problem. norht alabama. (think hot wet) if the cap is tight then seal the chimney. make sure the cap is tight. were talking masonary seal here no caulk. use a good sealer. I use Water Sealant from PK Prpfessional Inc. 1 800 676 7346 for a local source. no, I dont work for them, never called them just have used the product for 20 years. was reccomended to me. I got the # off a can. works good. be prepared to wash out your pump sprayer about 4 times with mineral spirits or to throw your your pump sprayer away. let me know. jim
I think that you either have a bad chimney cap or a flashing problem where the masonry meets the structure. I seriously doubt that the insulation has anything to do with it.