The first signs of deterioration in Louisiana-Pacific Corp.’s Inner-Seal house siding may be difficult to detect, say people who deal with the product.
The siding is found on thousands of homes across the country and the company has paid more than $46 million in claims to about 17,000 homeowners.
Inner-Seal comes in two types.
One is lap siding, placed in horizontal rows on the outside of homes. The other comes in large panels, with vertical lines, similar to what builders call “T-111” siding.
The bottom edge of the strips of siding, known as the “drip edge,” is the place problems first appear, said Bill Dost. Dost is former director of the Wood Building Research Center at the University of California, Berkeley, and expert witness in suits against L-P.
A crack appears on the drip edge that eventually turns black. That black coloration is likely mildew, Dost said.
Homeowners have even reported mushrooms growing out of the siding.
In some cases, nails appear to be sinking into the siding, other experts say. That’s generally caused by moisture getting into the siding and causing it to swell.
The siding is made of small chunks of aspen or pine that are mixed with glue and compressed. “When they get wet, they work back to their original shape,” Dost said.
The side of the house most exposed to the weather will show Inner-Seal problems soonest.
Experts differ on whether covering InnerSeal with vinyl or steel siding helps. That has to be done before moisture gets in the siding, which is hard to detect until there is major deterioration.
Regular repainting and keeping sprinklers from dousing the siding help prolong Inner-Seal’s life, L-P said.
People who suspect problems with their siding need to first determine if it’s L-P’s product. That requires contacting the builder or seller if the back of the siding, where the trademark is painted, is covered.
L-P insists the siding works well if handled properly. It has a customer hotline for people with questions and complaints. That number is 1-800-648-6893.
Customers are mailed a questionnaire and asked to take pictures of the problem. The company may then send an inspector to look at the house.
Homeowners are asked to go to L-P before contacting the Better Business Bureau.
The Washington attorney general is conducting an investigation into warranty claims. Washington residents may write the attorney general at 1019 Pacific Ave. South, Tacoma, WA 98402.