What are the mistakes to avoid when doing attic improvements?
Thursday, June 14, 2018
The three most common homeowner attic improvements are adding flooring for more storage space, a pull-down ladder for easier access, and more insulation for energy savings. All of them are sensible weekend-warrior projects that add value to a house if done correctly. But, done wrong, these simple improvements become a safety hazard and may even end up devaluing the house. Here’s our list of 6 attic improvement mistakes to avoid:
1) Removing truss chords to “open up storage space” - Roof trusses are an engineered assembly of pieces of lumber and metal connector plates, the sum of which is much stronger than the individual parts alone. They are designed so that the loads are transferred through the chords and webs to the bearing points at each end. Some parts of the truss are in compression (pushed inward) and other adjacent parts are in tension (stretched out) as the weight above and below the truss moves through them.
Removing even one piece disrupts the intended direction of the transfer of loads and weakens the truss. The fix can get expensive. Trusses are not even allowed to be notched or drilled without specific directions from the truss designer. The photo above is an example of what not to do and, while the roof may not collapse due to the missing webs, it is definitely weakened and vulnerable to sagging over time or damage in a windstorm.
2) Loose flooring boards - Plywood attic flooring should be nailed or, better yet, screwed into place. When a loose board shifts and then see-saws as you move across it, ceiling damage or a surprise drop-in downstairs comes next.
3) Installing flooring boards over electric cables - Installing floor boards directly over NM-cables (Romex®) that cross over the top of a ceiling joist or bottom truss chord will damage the cable sheathing and wire insulation. This can eventually causing a short, especially at the edge of a board. Leaving NM-cables loose above flooring also makes them subject to damage and they become a trip hazard in the dim light.
4) Insulation that blocks soffit vents - Most attics require ventilation that flows naturally from vents in the soffit at roof overhang to vents at the ridge. The only exception is a sealed attic with spray polyurethane foam (SPF) on the underside of the roof sheathing. Otherwise, ventilation is necessary to avoid overheating and high humidity. When piling on a second layer of insulation, be sure to install vent baffles or keep the existing ones open, to maintain the air flow.
5) Pull-down ladder mounted improperly - Attic ladders have specific instructions for fastener location and size stamped right on them. It’s usually a 16-penny nail or lag screw that the manufacturer wants. Any old fastener that happens to be handy won’t do, and may shear or come loose—and that includes drywall screws.
6) Pull-down ladder facing wrong way - When an attic ladder is near an outside wall and faces the wall, the area where you step into the attic often has low head clearance. In some installations, you have to exit the ladder to the side. When planning an attic try to situate the ladder to provide a landing area at the top of the ladder that is a stable platform with sufficient height and free of any cables to trip over, for safe attic entry.
One attic improvement that many newer homes with a cathedral ceiling over a centrally located living room area could definitely use is a second attic hatch at the other side of the house.
If you plan on exploring your attic anytime soon to plan your improvements, please read our blog post What are the hazards to avoid when going into an attic? first.
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