Wednesday, December 29, 2010
Posted by RV Doctor
I evidently have deformed lag screw holes in the floor frame for the bottom rear bracket where the patio awning is anchored. The original #14 x 2" screws now will not hold because the previous owner opened the awning with the pull strap next to the front upright, NOT with the strap in the middle of the awning, consequently twisting the rear upright and bracket, stripping the lag screws causing the damage. Is the only repair for this damage to drill out the holes in the bracket and install larger lag screws? If so what type of screw should I be looking for (galvanized, zinc coated, stainless?) and what size? #14 is the largest I can find in stores. Could drilling through the inside wall of the floor frame channel and then using a #14 x 2-1/2" lag screws solve the problem? How should I reseal the bracket? J., (Mosinee, WI)
In all honesty Jay, it would be difficult to provide proper direction without actually viewing firsthand, the damage caused by the misuse. A lot depends solely on how robust the floor structure is on your coach. If there is enough “meat” left in the good wood at the same screw location, then the obvious first attempt would be go to a larger lag screw. A #14 wood screw is significantly smaller than what I term “lag screw.” Take care not to re-drill the holes too large for the newer lag. Going to a longer lag will probably not be advantageous since the thickness of that floor member will rarely be wider than a 2X piece of lumber at best. I would suggest using stainless lag screws, 1/4-inch in diameter, if possible. Zinc-coated would be my second choice. If necessary, you could also go the distance and install 3/8-inch lags though it may be necessary to drill larger holes in the aluminum bracket.
For sealing, I’d use Eternabond double-face sealing tape behind the bracket, but I’d also squirt a bit of silicone sealant into the lag holes before installing each lag. Take care not to get silicone on the surface where the Eternabond tape will stick. Depending on the brand of your motorhome, it may be possible to access the floor void from underneath the coach by cutting an access hole in the bottom of the sub-floor. If this is easily accomplished, consider installing new wooden “cribbing” blocks inside the floor runner. Again, it would take a detailed inspection, but if this is doable, I’d opt for bolts with “T” nuts and lock washers instead of lag screws.