QUESTION: I saw a large traditional steel-framed house erected and enclosed in only five days. When completed, the house looked like any other. Are these types of houses very efficient and well insulated?
ANSWER: The number of steel-framed house kits being built is increasing exponentially and for good reasons. They are extremely strong (they can withstand 170-mph winds), energy-efficient, rustproof, fire- and termite-resistant and simple to build.
Steel-framed house kits range in size from 1,200-square-foot bungalows to elegant, contemporary 5,000-square-foot mansions with vaulted ceilings, lofts, dormers, porches, etc. When completed with brick, siding or stucco exteriors, they look like a typically built house.
Steel-framed houses are ideal for the do-it-yourself builder. All the steel framing members are pre-drilled, color-coded and numbered for your plans, so they bolt together like a huge erector set. You can purchase just the steel framing components or a complete house package with windows, doors, etc.
These houses have superior energy efficiency for several reasons.
First, steel framing produces a thicker wall than a standard wood-studded wall. This provides room for up to nine inches of insulation (for a rating of R-30).
Second, because steel has a high strength-to-weight ratio, framing members can be located on 4- or 8-foot centers instead of on 16-inch centers. This provides nearly continuous insulation (fewer thermal bridges).
Third, steel-framed houses do not settle. This means that, in 10 or 20 years, the house will still be very airtight and the doors and windows will still be square and true.
Fourth, steel framing can span 60 feet without interior supporting walls. This allows for more imaginative interior design and future remodeling. For passive solar or wood heating, the open design allows for better heat distribution.
A steel-framed house is typically built over a conventional poured concrete slab, foundation or basement with anchor bolts sticking up. Next, each I-beam framing assembly is bolted together on the ground.
Several workers carry each lightweight frame assembly to the foundation and tilt it up over the anchor bolts. Each successive frame assembly is bolted to the foundation and to each other with connecting roof purlins.
Horizontal steel furring strips are attached to the exterior with self-tapping screws. Standard one-half-inch plywood sheathing is screwed on.
To write for Update Bulletin No. 712, a listing of 11 steel-framed house and kit manufacturers, material and house specifications and eight floor plan layouts and exterior diagrams, include $2 and a business-size self-addressed stamped envelope and mail to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.
Double Flusher Needs a Closer Inspection
Q: I recently replaced the old valve assembly inside a toilet. Now I have to double flush the toilet sometimes. Did I do something wrong or is the new valve designed to use less water?
A: The new replacement valve assembly should not change the amount of water that is used per flush. This is controlled by the design of the tank and the flapper stopper valve in the tank bottom.
Check the tank water level. You may have it set too low. Make sure that you hooked the little flexible tube onto the overflow stack. This fills the bowl to form a water seal for proper flushing.
Condensate Fluid From Furnace Drain Is Acidic Q: We use a high-efficiency condensing gas furnace in the winter. A lot of water comes out of the condensate drain, and we have been collecting it in milk cartons for our plants. Is this just distilled water?
A: The condensate fluid from the furnace drain is not just pure distilled water. It is often highly acidic, with other chemicals in it. That is why the heat exchangers are made of special ceramic-coated stainless steel.
Do not put it on your plants or use it for any other purpose; just let it run down the drain as intended. In contrast, water from a dehumidifier is basically distilled water and can be used on plants.
Many Factors Affect Furnace Blower Speed Q: You had written about changing furnace blower speeds by adjusting the diameters of the belt pulleys. Mine has a belt drive. Is there a table of recommended pulley size settings available?
A: There really is no recommended size table to use. The actual blower speed depends on the speed of the motor and the relative diameters of the blower and motor pulleys, not just on the actual sizes of the pulleys.
If you want to know the exact speed or airflow, you will have to have a heating contractor check it. To speed it up a little yourself, adjust the motor pulley diameter bigger and the blower pulley smaller.
Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244. To read 150 previous columns, e-mail Dulley at https://www.dulley.com