Friday, November 21, 2008

Mold Growing on Ceiling

By Mark J. Donovan

If you have cathedral drywall ceilings and notice dark scallop patterns near the edge where the roof line hits the interior wall, chances are you have mold growing on the ceiling. This situation is due to the combination of poor insulation in the roof rafters and high humidity in the home.

Specifically what is happening is the cold outside area is transferring to the interior ceiling surface, and as a result the ceiling surface is becoming cold. When the warm, moist air inside the home comes in contact with the cold ceiling surface, condensation occurs in the form of small water droplets. These water droplets not only enable dust particles in the air to adhere to the ceiling, but also lead to the formation of mold. It is this dust and mold that shows up on the ceiling edges as dark spots. The reason it is a scalloped pattern is due to the fact that the cold transfer is less at the roof rafters. Thus wherever there is a roof rafter behind the drywall ceiling the less of a tendency for condensation to occur.

To combat this situation you can use a dehumidifier in the home. Secondarily you can add more insulation to the ceiling, albeit it is difficult to do in a retrofit situation. Blown insulation may be the best approach as small holes can be used to funnel the insulation into the ceiling. The holes can then be plugged and patched, and the ceiling repainted. Readmore »»

Home Insulation and R-Values

By Mark J. Donovan

Sufficient and proper insulation in the home is critical for keeping your home both toasty warm during the winter months and comfortably cool during the summer months.

When buying a new home, make sure the home inspection includes an assessment of the insulation situation within the home. Make sure the insulation is compliant to your local building codes, and preferably to the U.S. Department of Energy insulation R-Value guidelines. Note that there are different R-value guidelines for different portions of the home, e.g. walls, ceilings, in between floors. The U.S. DOE also provides different R-value guidelines for different regions of the country. For example in the upper New England area the recommend attic R-value is R-49, whereas in Florida it is R-38.

Note that R-value is a term for describing the resistance level to heat flow. The higher the R-value the higher the resistance to heat flow transfer. Depending upon the type of insulation used, the R-value varies between a value of 3 and 4 per inch of insulation thickness. For example a typical fiberglass insulation batt has an R-value of 3.14. Consequently an R-value of R-19 batt insulation is approximately 6 inches thick.

There are four main types of insulation used in the home and they include:

Batt or Blanket insulation - This is your standard fiberglass or Rockwool insulation material. It is used frequently in homes, and slides easily in between wall studs and floor and ceiling joists.

Rigid foam insulation - This is used frequently against basement walls.

Blown in Insulation – This is chemically treated, shredded newspaper that is blown into walls, attics, and between floor joists.

Spray Insulation – This is a two part liquid material that is sprayed onto walls, and between attic and flooring bays. As it hits the surface area it quickly expands and hardens to form a tight and highly insulated barrier. Readmore »»

Wednesday, November 12, 2008

How to Level Concrete Slab for Wood Floor Installation

By Mark J. Donovan

When planning to install a wood floor over a concrete slab, some will tell you to just apply a self leveling compound to the concrete slab and then glue down the wood flooring. This is a mistake!! Instead, build a network of sleepers (pressure treated 2x4s or 2x3’s over a layer of plastic). The plastic acts as a moisture barrier, and the sleepers act as support for both a wood subfloor and the eventual hard wood floor.

You may also want to add rigid foam insulation in-between the sleepers to add additional warmth to the flooring. Readmore »»

How to Fill in Large Concrete Channel in Basement Floor

By Mark J. Donovan

Sometimes when finishing a basement existing oil or plumbing lines imbedded in the concrete basement floor may need to be removed. In some cases it may be fine to just cut them back flush with the concrete floor and leave them where they lie. Other times, however, the lines may need to be cut out of the concrete basement floor. When this situation is necessary the question frequently comes up on how to fill the channel or large crack that is formed in digging out the lines. In addition you can use shims underneath the sleepers to create a level subfloor surface.

The answer to this question depends on the depth of the channel / crack. If the channel that is cut out of the basement concrete is deep, for example deeper than 2 inches, then Quickrete is appropriate for filling in the channel. If however the channel is shallow, e.g. less than two inches, it is best to use a floor leveling compound. Readmore »»

How to Fix Bubbles Formed under Drywall Tape

By Mark J. Donovan

When taping and mudding drywalls it is important to apply a sufficient amount of mud (joint compound) over the drywall seam first before applying the paper tape. If you do not put a sufficient layer of mud on the seam first, you will end up with bubbles forming underneath the dried drywall tape.

To fix the bubbles formed under the drywall tape, you can cut out the section of tape and redo it, or you can peal back the tape and apply additional joint compound under it.

Applying Drywall Tape Correctly

There is a technique involved in taping and mudding drywall that involves experience and some artistry. Use a 4” drywall blade to first fill in the joint seams and to apply a 4” skim coat of joint compound around the seam area. Next lay your drywall tape into the seam and lightly flatten it down into the joint compound using your 4” blade. Then apply a layer of joint compound over the seam and let it dry.

After the first coat as dried, lightly sand, and apply two additional coats of joint compound. Again, between coats, lightly sand. Also use an 8-10” blade for the second and third coats and flare out the seam to about 12” in width. Readmore »»

Sunday, November 2, 2008

Weatherstripping and Caulking Storm Doors

By Mark J. Donovan

With daylight savings time now behind us, and cold weather right around the corner, I decided today to replace the storm door screen insert with the glass insert. In the process I noticed that there were several air gaps around the periphery of the door. Seeing these future winter air draft culprits I immediately jumped into my car and visited my local home improvement store. While there, I picked up door and window caulk and weatherstripping.

With caulk and weatherstripping in hand I returned home and caulked all around the exterior of the door and added weatherstripping along the inside door frame.

In the process of installing the weatherstripping I saw that I still had a rather large gap at the bottom of the door near the handle. To remove the gap, I first lowered the adjustable kick plate a little. It solved most of the gap, but not entirely. To fully eliminate the gap I adjusted the closer plate on the bottom portion of the door. By effectively stretching out the reach of the door closer another 1/4th of an inch the closer now has sufficient tension to fully close the base of the door.

So with just a few minor insulation and mechanical tweaks around my storm door, it is now air tight and ready for the long winter. At least now, however, I can let a little more light into the home during the short days without cooling off the house. Readmore »»