Skylight Works Better With White Light Well

QUESTION: I will be installing a skylight in my living room and I’m a little confused about whether I need a light shaft, and how to go about constructing one. Can you shed some light on this?

ANSWER: When you are dealing with a ceiling other than a cathedral type, you will have a space between the skylight unit and the ceiling below. The size and shape of this light well or shaft depends on various factors--the construction of the roof and ceiling, the desired amount of light to enter the room, and the appearance of the entire area.

If you want a light shaft, simply frame out the area between the roof rafters and the ceiling joists with appropriate lumber. Keep in mind that this shaft can be designed to extend straight down into the room or be aligned perpendicular to the roof opening so it comes into the room at an angle. Box in the shaft with plywood, drywall or paneling. Finishing off with white paint will better help reflect exterior light into the room.

Insulation, Vapor Bar Can Warm Cold Walls

Q: My foundation is made of 10-inch concrete block up to ground level and then 6-inch block above that point with a 4-inch stone facing. The inside surfaces of the outer wall are plastered directly onto the block. These walls feel cold to the touch.

I recently visited Florida and saw several similarly constructed houses, but their block walls were covered with sheets of insulating material, furring strips and plastic vapor barrier. Would adding insulation and a vapor barrier solve my cold wall problem?

A: It sure would, especially if you install drywall over the insulation and vapor barrier. First, check the type of polystyrene you use. Some are effective water barriers in themselves. The ability to deter the passage of moisture is measured in perms. Any material having a rate of less than 1.0 is considered an effective vapor barrier. Styrofoam brand insulation has a perm value of 0.6 for each inch of thickness. Since polyethylene (plastic vapor barrier) film is inexpensive, you should use it to ensure a continuous vapor barrier over gaps and joints in the insulation.