One of the advantages of using parallel strand lumber (PSL) products is that they can be treated and offer great resistance to the elements while also providing the advantages of composite lumbers. Weyerhaeuser provides literature on what factors to apply when considering treated products, which weâve integrated into ClearCalcs.
Select any regular PSL product from our member selector:
Once youâve selected the PSL, an option will appear asking you if your member is treated or not. Set it to âYesâ if it is indeed treated
If youâre specifying treated PSL, itâs quite likely that youâre not expecting it to stay dry. Weyerhaeuserâs literature considers three separate service conditions (Service levels or SL 1 to 3) as opposed to the two (wet vs dry) in the NDS. By default, we assume Service Level 2, which would be applicable to a member exposed to regular weather. If youâll be staying dry (SL 1) or your PSL member will be in constant contact with water or the ground (SL 3), scroll down to the Design Conditions section and change as required. Thisâll change the service condition factors which determine the strength.