 | Siding,
manufactured from oriented strand board and other wood composites, have the
advantage of being manufactured from relatively low cost wood and young
trees, thus saving money and attempting at a more benign impact on the
environment. Such siding products became more attractive as traditional wood
siding decreased in quality and/or increases in cost. Unfortunately, most of
the experience with such siding products have been poor. Most of these
products have experienced moisture related problems.
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| Louisiana Pacific Corp. came out with an Inner-Seal Lap Siding (LP Siding).
Masonite developed Omni-Wood, and a number of other companies launched other
similar products. Of all of these products, LP is the best known, but for
the wrong reasons. LP has been involved in a highly publicized legal action
and has agreed to pay for some siding damage, see the LP Litigation
Information Page.
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| The key issues relating to the longevity of LP and other manufactured wood
siding products seem to be as follows:
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| 1.
A better formulation of the materials and the manufacturing process. |
| 2. A better formulation of the materials and the manufacturing process.
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| 3. Good quality installation and careful attention to manufacturers
installation and maintenance instructions. |
| 4. Low interior moisture levels, good venting systems, wide roof
overhangs and the proper control of vegetation next to the house.
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| One of the problems with this type of siding is the requirement that it
must be installed with "hidden fasteners", and not "face nailed." Each piece
of siding is nailed along the top edge of the board, the nails are then
covered by the next layer of siding. This requirement is intended to prevent
water entry into the core of the material. Failure to follow these
instructions has contributed to many of the damaged siding installations.
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| This "hidden fastener" requirement makes partial replacement of LP type
siding very difficult. When replacing wood lap siding, a damaged piece is
carefully removed and a new piece installed. The new piece is then face
nailed into place. With LP siding repairs, such face nailing needs to be
minimized and carefully caulked, or the siding needs to be glued into place.
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| Methods to reduce additional de-lamination - Before doing anything, it is
very important to find out what if any help is available from the siding
manufacturer. Following all of the manufacturers maintenance guidelines may
be required in order to keep any warrantee in force. If the siding shows
some swelling or thin fissures at the bottom edge, it may be possible to
reduce further damage by priming the siding with "Permenizer Plus" or a
similar primer and then repainting. The primer and paint may be applied with
a spray gun, but the bottom edge and any other areas of defects must be
brushed.
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LP Siding Maintenance:
| Some of the pre 1996 versions of the LP and similar siding products failed
soon after installation. Later versions have lasted longer but as of the
fall of 2004, I have yet to see such a product that stands up in our wet
Pacific Northwest Climate. The most common conditions which seems to warrant
some "preventative" maintenance and eventual replacement are: limited
swelling and thin cracks along the bottom edge of the siding.
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LP (Louisiana Pacific Co.) does not seem to have any official
recommendations about the maintenance of such siding. However, some of the
LP staff and other suggest the following:
| Quality caulking of any dimpled nail heads and other holes etc. |
| Priming with Parker "Flex Bind", Pittsburgh "Permenizer Plus", or
similar primer material. Note: brushing the primer into the bottom edge of
the siding is a critical element of this work. |
| Keeping vegetation, soil, roof drainage and sprinkler water off the
siding.
This type of maintenance work is unlikely to solve all of the problems
with this type of siding or help with severely deteriorated material but
it should prolong the life of the product.
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How long can the damaged siding be made to last? Will this maintenance
work help? Nobody yet knows, and no one will know until the siding fails
completely. But if I had some slightly damaged LP siding on my home, I would
invest in this type of maintenance work.
Note:
The Information contained within this website is for informational purposes
only. Kevin M. Leonard & The Home Inspection Company always recommends that
a qualified expert be consulted in the area of concern.
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