Siding Inspections for LP or Hardboard Siding in NW Washington

Hardboard or Composite wood sidings are made from various combinations of wood veneers, fibers or flakes, bound together with glues, resins, and/or waxes. They come with different names, LP siding, T-11,  Plywood, oriented strand board (OSB), and hardboard are basic engineered wood siding materials. Several different types and brands of engineered wood siding have experienced moisture-related failures due to product or installation defects, or improper maintenance. For the purpose of this article we will refer to these products as composite siding. Generally speaking homeowners with siding installed after 1996 will have fewer problems than those installed prior to that. There have been many class action suits against the manufacturers of earlier product. For many homeowners, the time has passed to receive any compensation from the class action suits however most of the composite products did have a warranty and manufacturers such as Louisiana Pacific are paying warranty claims. While Louisiana Pacific (LP) was the most publicized there were many other companies who also made this type of siding.

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. Many homes in the NW Washington have been sided with composite or OSB siding. These products have  been problematic  in the NW Washington due to lack of maintenance, the weather and moisture conditions.

Locally Used Manufacturers

At the forefront of Siding Problems in the NW Washington is a product called “Louisiana Pacific” or “LP” (Inner Seal) Siding. There was a class action suit filed against the Louisiana Pacific siding, covering individuals who installed the product prior to January 1, 1996. The class action suit does not cover LP Inner Seal Siding installed after January 1, 1996.

Louisiana Pacific sold two basic types of LP (Inner Seal) siding, “Lap” or horizontal siding and LP (Inner Seal) Panel Siding. Many people refer to the Panel Siding as T1-11. This is not a correct reference as T1-11 siding is a true plywood siding and it is made quite differently from the LP (Inner Seal) Siding and has held up better than the older LP Siding.

If you need more information on the warranty claims your can call their claim line at 1-800-450-6106 When you put in a warranty claim it will take about 90 days for them to send out an inspector. You can realistically expect that it will take from one year to two years from the date of inspection to the date that you will actually receive your claim check. The amount of time it will take from date of inspection to date of check could change but we expect it to get worse and not better over the next few months.

Omni Board is another product that people in the NW Washington are having problems with. The Omni-Board product is very similar to the Louisiana Pacific product in that it is a type of “chip board” or composite product.

Omni-Board, like Louisiana Pacific, sold both “Lap” and “Panel” Siding. However, unlike the Louisiana Pacific panels, we do not always suggest that you side over these panels. The Omni-Board panels tend to bow more than the Louisiana Pacific Panels. As a result of the bowing, material set on top of the Omni-Board Panels do not always sit flat and can give the home the appearance of being “out of square”. Caution is the better part of valor when siding over the Omni-Board panels.

You may call the Omni-Board claim line at 1-800-323-4591. It should only take you from 3 months to 6 months for Omni-board to settle your claim. Dealing with Omni-Board is much easier than Louisiana Pacific at this time. It is important to note that there is not a class action suit on the Omni-Board product. The company is handling the claims under their warranty program.

Masonite Hard Board – (Masonite) – did have a class action suit filed. The hard board siding was not used a great deal in the Pacific Northwest but you do find it from time to time. Most of the Masonite hard board siding came in panel form. On expensive homes you might find the Masonite “clad board”. This is where Masonite covered the composite siding with a “stucco” appearing material. This material was used on houses where people wanted to have a “tutor” looking home. If you have Masonite Hard Board siding you may call their claim line at 1-800-330-2722.
Georgia Pacific Corporation recently settled a class action suit regarding their Jarratt Lap Siding and Catawba Siding. Catawba was used a great deal in NW Washington when Louisiana Pacific started having problems with their siding. You may call the Georgia Pacific corporation claims line at 1-888-882-5246.
Weyerhaeuser brand hardboard siding is an exterior composite wood siding made from wood fiber mixed primarily with resin and wax and pressed under extreme pressure and heat into dense panels. Using different plate designs, these panels can have different textures. The panels can then be cut into long horizontal lap siding, or into sheets to make panel siding.

Most Weyerhaeuser composite siding is designed with a cedar wood-grain texture. Other textures include a stucco texture, smooth lap siding, a cedar shake texture or a cross-sawn wood texture. Since these textures are very realistic, it can be difficult to tell them apart from other kinds of siding. There may be repeating features such as knots spaced 61″ apart, or a “double knot” feature with two non-identical knots spaced 12 1/8″ apart. If you can see the back, most styles contain the marking “AHA 10” or “AHA 20”. New class action suit filed in June, 1999

For claims call 1-253-924-2655 or 1-800-365-0697 Claims information can be found at Information on how to identify Weyerhaeuser siding can be found here.

Other Manufacturers

We have limited information on other manufacturers mainly because we do not see their product often in this part of the country.

Mail your claim to: Boise Cascade Corporation, Timber & Wood Products Division, P.O. Box 62, Boise, ID 83707, Attn: Tana Rasmussen; phone: 208/384-6162; Include six photographs, one of each side of your house from a distance and two close-ups that will clearly show the problems you are experiencing. c/o Tana Rasmussen.
This company no longer manufactures or markets lap siding. They continue to produce a hardboard panel surfaced with tempered hardboard marketed as Duratemp. Need to submit a claim to Stimson? Mail your claim to 520 S.W. Yamhill, Suite 325, Portland, Oregon, 97204-1319; Remember to send a few photos of your siding with your claim letter.
Claims information can be found at

This product has been out of production for a few years but damaged products continue to surface. A proposed settlement has been reached in a class action lawsuit concerning a siding product known as Cladwood. The settlement would provide compensation to persons who have incurred property damage resulting from failure of Cladwood siding installed on their homes or buildings. For claims call 1-888-572-3897.

Panels manufactured before 1992 have been reported have problems with the way that they were processed.. There have been some complaints of the cedar shingles separating from their plywood backing. Poor installation techniques appear to be a major contributor to this problem. This product has been improved and seems to be exhibiting fewer problems.

Fiber-cement Products

Fiber-cement siding has the look of wood siding but has a lower cost and lower maintenance. Market share is approaching ten percent, according to manufacturers. Most newly constructed homes with lap siding with have this type of siding. Additional benefits include resistance to termites and fire. Fiber-cement siding will not rot, buckle or warp and holds paint for several years longer than conventional wood siding. Moisture resistance is a concern, but problems can be avoided if the siding is installed correctly and properly treated.

Listed below are a few of the most common installation defects that I find.  The funny thing about these installation defects is that the installation instructions are very clear and very specific – the diagrams below all come directly from James Hardie.  The other manufacturers of fiber cement siding have nearly identical installation instructions.

Improper Clearances

  • Must be kept 2″ away from roof surfaces, decks, driveways, steps, and other similar hard surfaces.
  • Must be kept 6″ above the finished grade.
  • Gutters must be kept 1″ away from the siding, and kickout flashing needs to be installed.
  • Must be kept 1/4″ above flashing above windows, and not caulked at the z flashing

Improperly Attached

  • Must be blind nailed or face nailed, but not both.  The photos below show blind nails and face nails used together, and clearly shows what happens.
  • The proper size nails must be used (6d or siding nails).  Framing nails (16d) were used in the photos below.
  • The nails must be driven in straight, and must not be over-driven or under-driven.  The nails pictured were driven at an angle or driven in too far.

This product appears to perform very well in moist environments. Fiber-cement siding manufactured by James-Hardie Company (Hardi-Plank, Hardi-Panel, and Hardi-Home) have gained product recognition and an increasing market share.

If you have an existing installation and you want to know if it was properly installed, you can view some of their older installation manuals here:

2001 Hardiplank Lap Siding Installation Instructions
2005 Hardiplank Lap Siding Installation Instructions
2007 Hardiplank Lap Siding Installation Instructions
2008 Hardiplank Lap Siding Installation Instructions
2010 Hardiplank Lap Siding Installation Instructions

Certain Teed – Wolverine Dura-Press

This product has been renamed Weatherboard and is being marketed under the Certainteed family of products.

Manufacture Maxipanel, Maxiplank and Maxishake products

Not sure what you have? Siding Solutions Identification page

Composite 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, we have yet to see such a product that stands up in our wet Pacific Northwest Climate unless it is vigilantly maintained. 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. See the first picture below for an example of this condition

Regular application of a good quality exterior paint is critical to successfully maintaining composite siding. Although one would expect the area painter to know the areas of composite siding that needs special attention, we have seen enough poor applied or sloppy paint jobs that a gentle reminder is in order. Make sure that all joints are caulked and that paint is sprayed up into the overlaps of the siding. Many painter tend to spray “straight ahead” however the areas that really need the paint are the bottom edges and directly behind the bottom edge. See the pictures below for examples.

Other maintenance practices:

  • quality caulking of any dimpled nail heads, abuttment joints, any areas where water may sit or pool and around fixtures such as lights or hose bibs
  • 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.
  • make sure sheathing has at least 1/2″ clearance where to roof and side walls of the home join together. These joints are normally covered by trim and not exposed.

Painting 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.

Examples of Siding issues

Early Deterioration and warping.
Note fungus growing on bottom edge.
Different angle of same siding Delaminating around nailing point Closeup of delamination or "checking" Soft spot. Deterioration to
the point where siding crumbles
Edge Checking and swelling. Although each
manufacturers product varies slightly the
bottom edges should be around 7/16" thick
with no swelling present. This area has
swelled to over 9/16"
Edge Rotting Fungus growing on edge

Should I buy a home with LP or any other composite siding?

First, not all composite siding is bad. Initially I would qualify the age. If it was manufactured prior 1998 it may be first generation products which had a higher rate of failure. to If there are any signs of the composite siding failing, we advise getting it evaluated before purchasing a home. Why? When you buy the home the siding issues are now yours to deal with! It takes your time and your money, once you own the home. In most areas like the Pacific Northwest, composite siding has a finite lifespan like a roof does. It takes meticulous maintenance of the siding to extend its life beyond twenty years. This is the “short answer” to “should I buy a home with lp siding on it.” As with all things it’s entirely your call, well unless you are getting financing.

The Short Answers:

Should I buy a home with LP siding on it if I’m paying cash? I wouldn’t, unless you own a siding company or have the repair costs deducted and have some spare time on your hands. Get the lp siding issues fixed first.
Should I buy a home with LP siding on it if I’m getting financing? You may not have a choice. If there are any signs of LP Siding rot, delamination or failing the chances of passing inspection are very slim. And if the home fails inspection for LP Siding issues many lending companies will not approve your financing – hence you may not have a choice.

I have failing Composite Siding, what should I do?

The Short Answer: the sooner you get it fixed the better.
If your LP Siding is already showing signs of rot, delaminating, fungus, mold, swelling, mushrooms or separation – it’s just a matter of time before you have a real problem on your hands. Your first step should be to get a unbiased opinion on the extent of the damage. You may want to call a contractor but remember they are in the business of replacing siding and can be biased. You will be better off with a certified siding inspector such as Pacific Crest Inspections. We can gauge the extend of the damage using industry guidelines to determine the extent of the repairs needed.

In many cases the deterioration has begun and but still within the industry guidelines so replacement isn’t warranted, yet. Your best bet is to stabilize by cleaning, re-caulking and painting the siding. You may still end up replacing the siding but can postpone that investment by aggressively maintaining it.

Most siding companies pull off all of the LP lap product and install new hardi-plank, vinyl or cedar. However, some siding companies re-side over the LP panel siding instead of pulling the panel material off. This process can have cost benefits; but, prior to siding over the panels you should look to see how much damage there is to the panels. If the damage is too severe, we do not suggest siding over the panels. Additionally, in many cases we do not suggest siding over the panels with vinyl.

Most builders placed either OSB or plywood behind the “Lap Siding”. So, if you take off a piece of lap siding you have another protective layer of material before you get to the cavity of your wall. The panel siding is what we call a “single wall construction” type product.

If you pull off a piece of panel siding it will immediately open up the cavity of your wall. You will be able to see your wiring, insulation, plumbing etc. This is one of the reasons so many siders suggest siding over the panel siding. By siding over the panel siding it gives you a second layer of protection. Thus the terms… “single wall construction” (panels only) and “double wall construction” (lap siding followed by a layer of plywood or chipboard). We do not suggest that you side over any panels that are seriously damaged. Usually the most damaged panels can be found in the non-insulated areas of your fireplace chimney or over the garage entrance. Chipboard products are often called “OSB” – oriented strand board.

Some siding companies claim that you cannot put vinyl over hardboard siding, not true according the the National Association of Home Builders.

Liquid vinyl siding – the answer to your siding problems???

Liquid vinyl siding problems are recent, since liquid vinyl is a relatively new exterior coating. Unlike vinyl siding, liquid vinyl is a spray-on, viscous coating that can be applied to any paintable surface. It dries to the touch in minutes, but requires about three weeks to set. However if you hardboard siding is damaged or moisture laden, liquid vinyl may not adhere and properly protect your siding

As with any exterior vinyl product, whether siding or coating, the surface to be covered must be in perfect condition. Preparation of the surface, and installation, are critical to the prevention of problems. Moisture has been the central issue in siding products, and that leads back to proper treatment of the substrate and installation that meets known standards for liquid vinyl.

Installation instructions for liquid vinyl are well-known, but not always followed. Any underlying mildew, dry rot, or mold must be removed from the substrate. If necessary, any defective area must be replaced. No imperfection in stucco or wood can be overlooked. If faulty installation leads to future problems with moisture, mold lawsuits will be among the litigation that follows.

After sanding, caulking, and scraping, a primer is applied that is a bonding agent. Last comes the liquid vinyl coating. This elastic, water-resistant coating is a breathable film that eliminates moisture, and is guaranteed for 50 years. If, however, preparation of the substrate and actual construction standards are not maintained, moisture-related liquid vinyl siding problems can develop and building product lawsuits will result.

Many of the companies who install this product are subcontractors or independent companies and their experience will vary. Ask how many times they have applied this product and what issues they have seen.  I would always do a check with the Better Business Bureau and ask for at least three reference customers to talk to.

Ask The Builder article on liquid siding