Skip to: Content
Skip to: Site Navigation
Skip to: Search


Ask an Architect

By Richard A. Kent / March 22, 1985



Q I own an office building which has approximately 60 fluorescent light fixtures in a suspended acoustical-tile ceiling. Would it be economically feasible to change bulbs to the new energy-saving type? A reader

Skip to next paragraph

I would assume the fixtures contain four 40-watt lamps each plus two ballasts.

To switch to 30-watt lamps and energy-saving ballasts amounts to an approximate saving of 8 watts for each item, or about 48 watts per fixture.

The saving is nice, but the ballasts are expensive, as is the labor to change them. Also, the light (lumen) output of the lamps themselves is about 30 percent less.

I would be wary of changing bulbs in task areas, but I would not hesitate changing them in corridors or areas where minimal visual tasks are being performed. Q The water pipes in my very old home are corroded and must be replaced. The plumber tells me that copper is the most economical replacement, both in labor and material. Our family has always avoided using copper in eating or food-preparation vessels as it is believed to be harmful. I have talked with one person who reports a green tinge in faucet water after installation of copper pipes. What is your recommendation?

Mrs. Rowena Zarr

Omaha, Neb.

Several million homes in California are plumbed with copper water pipes, and I have never seen a healthier lot. Because of copper's flexibility and long lengths, there are fewer connections to make, which reduces installation costs. Leaky joints or places where the copper is exposed to air and water is where the green may be seen. This is copper's form of rust or oxidation.

Proper connections must be made where the new copper joins the old galvanized pipe, as the dissimilar metals cause electrolysis which greatly accelerates the deterioration of the pipes. Your plumber is sure to use proper couplings so this doesn't occur.

If you have any doubts, call your local department of building and safety and speak with the plumbing inspector. Q I have a second-story deck that has 8-by-8-inch ceramic tiles over it. Rain and moisture have gotten under the tiles and are ruining the wood underneath, even though there was a layer of something or other placed under the tiles before they were laid. I was told that all the tile had to be taken up, which means a $2,000 job wasted. Could you recommend a coating which will keep the moisture out?

Alberta Hale

Fredericksburg, Texas

Ceramic-tile distributors generally carry sealers, but I have found them to be of very little value on exterior decks. As a temporary measure I would recommend caulking around the edges, where the cracks appear, with a clear silicone sealant. This is where most water intrusion usually occurs.

From your description, it seems the tile deck was improperly installed in the first place.

A proper installation, assuming you have a structure of adequate stiffness underneath, is similar to that of a shower pan.

The wood deck would first be coated with a hot-mop asphalt roofing membrane, properly flashed to the walls or deck edges.

Next, a minimum 11/2-inch-thick reinforced concrete grout bed would be placed, after which the ceramic tile would be set and grouted.

In most instances, this installation would never leak as the stiffness of the concrete would not allow the grout joints of the tile to break down. Any water which would get through would be stopped by the waterproof asphalt membrane.

Should you determine that removing the tile deck is the best answer, I would recommend replacing it with a continuous membrane system, such as Dex-O-Tex, made by Crossfield Products Corporation. You can get the name of its nearest applicator by writing to P.O. Box 322, Pascagoula, Miss. 39567.

This, and similar types of decks, are quite reliable and inexpensive.

If you have a question on designing, improving, or maintaining your home, school, church, or place of business, send it to the real estate editor, The Christian Science Monitor, One Norway Street, Boston, Mass. 02115. Richard A. Kent is a practicing architect and general contractor in southern California.