I want to build a super-insulated house with very low utility bills and do much of the work myself to lower the costs. What type of construction can I use that does not require expensive equipment? J. K.
A - One of the most energy-efficient do-it-yourself construction methods utilizes snap-together hollow insulation foam blocks. It is very easy to build yourself and produces a highly insulated and airtight house with low utility bills. When finished, these houses look very conventional.Once you snap all the foam insulation blocks together to form the foundation and walls, you slip standard steel reinforcing rods in the cavities. Then concrete is poured in the hollow cavities.
The concrete flows throughout all the cavities and forms a solid monolithic insulated concrete wall. The finished wall insulation values range from R20 to R30 depending on the specific design of the foam block.
Each foam block (usually made of expanded polystyrene foam) is roughly 10 inches square by 40 inches long and weighs less than four pounds. The blocks for an entire house weigh only several hundred pounds.
In addition to low-energy usage, strength and termite resistance, these houses are very quiet. The combination of the heavy concrete mass and the foam on both sides stops much of the outdoor noise.
Another energy advantage of a concrete/foam block house is the thermal mass of the walls themselves. The heavy concrete in the block cavities stores heat in the winter. In the summer, it moderates the indoor temperature rise as the outdoor temperature rises during the day.
You can finish the interior by gluing drywall directly to the interior foam insulation surface with a special adhesive. The exterior can be finished with stucco, siding, brick or stone.
For exterior siding, nails are pushed through the foam block from the inside hollow opening before the concrete is poured. For a brick exterior, ties are pushed through the foam insulation as with the siding method.
Another similar type of construction uses larger hollow foam blocks that are made of a mixture of 10 percent concrete and 90 percent foam beads. Since the concrete adds strength to the blocks, recycled foam material can be used.
This special concrete/foam mixture is still very lightweight, only about 37 pounds per large wall section. These types of blocks also provide exceptional fire resistance. Once the wall panels are stacked together, concrete is poured into the cavities.
You can write to me for UTILITY BILLS UPDATE No. 384 showing manufacturers, addresses and telephone numbers of do-it-yourself insulating concrete/foam blocks and for construction details and specifications. Write to James Dulley, The Deseret News, 6906 Royal Green Drive, Cincinnati, OH 45244. Please include $1 and a self-addressed stamped business-size envelope.
Q - Does it really save much electricity by trying to stop opening the refrigerator door as often? P. D.
A - For a typical family, the refrigerator is opened roughly 45 times per day; however, some larger families may break 100 openings per day. Some studies have shown only a relatively modest reduction in electricity usage by opening the door less often.
For the best efficiency, keep the refrigerator condenser coils clean and keep your refrigerator and freezer moderately full.