Home>Discussions>INSULATION & HVAC>Attic Insulation insuffiecient, No air movement, Plaster bubbling! HELP
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Pash0701
Attic Insulation insuffiecient, No air movement, Plaster bubbling! HELP
Pash0701

I have an older home that was built around 1912. It is a great home with 10 1/2' ceilings. We have a chimney that goes up through the middle of the home, and it is not visible. (Meaning there is plaster over the brick.) We also have a fuel oil furnace. We have noticed that the plaster is bubbling on the ceiling around the chimney on 2 sides. I have been up in the attic and the air flow is not good. The roof was replaced and there were no whirly birds, which I have since added. Also there are not vents on the soffits, which I will be adding. In the winter months, the attic is very cold and gets frost. Then it heats up and the frost melts. Up in the attic, I pulled the insulation away from the chimney and there isn't actually a hole in the plaster, but the paint on the ceiling has basically "let go" from the plaster. I have a few questions on what to do with this:

1: I know I need to add insulation in the attic, but I would like to figure out if I need to do anything with the chimney first. (Line it????)
2: How can I fix the plaster around the chimney? (Big willy's plaster repair?) One spot is bubbled up.
3: Where do I start with air flow in the attic? I have whirly birds, will add soffit vents. Anything else?

I appreciate the help.

-First time homeowner!

dj1
Re: Attic Insulation insuffiecient, No air movement, Plaster bubbling! HELP
dj1

1. Before you add insulation, fix all leaks.

2. The best fix is to remove the bubbly stuff and re-do it. What kind of repair? depends on the amount of damaged plaster.

3. Whirly birds (we call them Turbine Vents) are great, if you have enough of them. Otherwise, a ridge vent will be able to provide the air flow you will need with your new soffit vents.

Mastercarpentry
Re: Attic Insulation insuffiecient, No air movement, Plaster bubbling! HELP
Mastercarpentry

I'd recommend adding a ridge vent along with ventilating the soffits. Turbine vents aren't pretty, are pretty easy to damage physically by falling limbs etc, they can leak at the flashing, and the bearings eventually fail. Sometimes they are a good idea but there are better ways now ie ridge vents. Next I'd pull back the insulation and fire-caulk where any pipes or wires etc penetrate the top wall plate. Now insulate correctly, being sure to maintain code-required clearance at the chimney where fireproof insulation such as rock-wool may be used. It's one-and-done this way with everything as optimum as it can possible be made.

I'll leave the plaster repair recommendations to those more experienced with it- it's not my bailiwick at all.

Phil

keith3267
Re: Attic Insulation insuffiecient, No air movement, Plaster bubbling! HELP
keith3267

I do not want to discourage your from properly venting your attic, you should do that for a number of reasons, but it might not solve your problem. The problem could be the mortar used in the bricks above the roofline. When the mortar gets old, it can develop cracks, become porous, or loose its bond with the bricks, any or all of which allow water to make its way through the mortar and to the inside of the bricks.

The bricks them selves can become porous and act like sponges over time. They get wet and they in turn soak the plaster in the ceiling next to them and cause the paint to peal in that area. You may need to waterproof your chimney. You will need to contact a spe******t in this area.

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