Archive for the ‘brick’ category

Insulation Near a Fireplace?

December 17th, 2013

Question:

Can I insulate the underside of my first-floor fireplace chase? I would like to put batt-insulation, and a ceiling below the fireplace. I currently use the area as a storage closet. The area is very cold, and the air seems to migrate upstairs. I also get frost above the basement wall, on the framing. The fireplace is ~20 years old, and non-gas.

–Eric

Answer:

You’ll need to check on the installation requirements for your specific type of pre-fabricated fireplace. They must be installed per specific installation requirements. In general, they require clearance around the metal firebox, and around the metal flue that is routed up through the boxed-in chimney chase. I don’t think your real problem is in the basement. I think the real problem is the exterior wall behind the fireplace. Insulating below the floor will be of little value.

The areas around the fireplace can be a big heat-loss, because the outside wall behind the fireplace may not be properly insulated. The exterior wall should be framed so that it can be insulated and sealed like a typical exterior wall. This does not always happen when the wall is buried behind a manufactured fireplace, and brick facing.

F007 - Metal-Framed Prefabricated FireplaceThe area below the fireplace (above the foundation wall) should be independent from the fireplace installation. Ice in this area (and around the sill/band joist) occurs because air moves through the fiberglass batts, and moisture condenses on the cold surface.

The ideal fix at the top of the foundation wall is to have the area sealed and insulated with spray foam. This will seal the air-leaks, provide a vapor-barrier, and insulate the area.

If you want to work with fiberglass, you need to remove it and caulk any gaps in the area around the sill-plate to the sub-floor. Fill the space with tight-fitting fiberglass, then seal it with drywall and plastic caulked in place on the heated side. It sounds like the foam is a much better option.

–Mr. Fix-It

Natural Fireplace Maintenance

February 8th, 2013

QUESTION:

We have a natural fireplace, not gas. Can you tell us the maintenance we should be doing on our fireplace? What is the maintenance on a gas fireplace? Should we be having our chimney cleaned out by a professional? Is this necessary?

JIM

ANSWER:

F005 - Masonry FireplaceFor a typical wood burning fireplace, you should have the chimney cleaned and inspected every several years. The cleaning depends on how often you burn wood. If you burn most weeks, clean the chimney every year. If you burn a few times per year, clean the chimney every few years.

With a gas fireplace the maintenance is limited because the products of combustion are relatively clean. The fireplace logs should not be producing excessive soot and they should be checked along with the chimney flue every couple of years.

With either fireplace, you should also make sure the damper is closing tightly when you are not in use. You should make sure the damper opens fully and latches open when you build the fire. Outside there should be no bird or animal nests in or around the chimney.

For a masonry chimney, the cap should be solid and overhang the structure of the chimney. The structure should be solid without salt stains or surface spalling. For a framed-in metal chimney, it should have a cap that directs water away from the flue with limited rust. The box should be in good condition just like the siding of your home.

With either type of chimney, I think it is important to have a rain cap on the flue. They keep water and animals out of the chimney flue. When in doubt about chimney or fireplace issues, have a professional check it out.

White Stain on Brick Chimney

February 23rd, 2010

We had a new brick chimney installed last June by a reputable local company. In the fall a small area at the base began to show a frosty look. Now in the winter, the entire brick unit (top to bottom) is white. It’s even difficult to tell the color of the bricks. Is it a flue pipe installation error, or something in the brick ? I enjoy your program. Keep us homeowners informed.

Answer:

The white stain is from a moisture problem. The moisture moves through the brick and mortar, and deposits the white, lime, salty deposit. It could be from many possible problems – cap, flashing, flue, original work, etc.