Lp siding also known as Louisiana Pacific siding is a wafer board style siding also call osb which stands for oriented strand board. It is particle chips of wood glued together. Lp was formerly located in the Sherwood- Tualatin area which is one reason why there is so much in the northwest. Over the last few decades, siding contractors would use it because back then Lp had a decent reputation and it was always in stock so general contractors could most likely meet scheduling needs. The problem occurs when it gets wet with rain it starts to swell and often will start molding & growing fungus underneath where the moisture doesn’t dry out. How can I tell if I have Lp? It has a specific trademark knot which is about as big as a silver dollar and hidden in the knot are the letters Lp. If you haven’t seen it before it is very hard to see the first time. You need to look very closely as some are more defined and others are more blurry. Another problem is that Lp panel style 4 x 8 sheets, also called t1-11, are nailed directly up to the studs with no moisture barrier to protect the studs. Many homeowners don’t believe this but its true. The mold then gets on your studs and starts to rot them because no light gets under your siding and mold likes dark. This will generally happen in specific areas where rain is slowly trickling in over time but wont be on all all the studs of your home. Over the last 2 decades we have also found that some siders don’t put building house wrap under the horizontal siding either. This is CRAZY and illegal!
If your house is built AFTER 1985 you may have Lp siding. If any your neighbors have replaced their siding chances are even greater that you have it too as siding contractors often use the same products when developing a neighborhood. Typical products homeowners use when replacing their siding is fiber cement commonly called Hardi Plank & Certanteed Weatherboards. Others pick cedar or vinyl siding. Superior Exterior Systems has almost 20 years of experience & give free inspections. We can immediately verify if indeed you do have Lp. For even more info & pictures of what to look for visit us at http://superiorexteriorsystems.com/ or simply call us at (503)285-0875 or (360)687-8936. Thanks for listening.
