New deck surface, best method of leveling
MashedThumbs
| Posted in Construction Techniques on
I’m putting down a new deck surface and am curious about various methods of leveling it. The project is to put a layer of ACX plywood over an existing deck and coat the plywood with a ureathane material (BASF Sonoguard). The existing deck constructed of 2×6 screwed to the framing is in good condition with minor cupping in a few locations. The framing is sound and quite stout. The plywood is to be screwed to the 2×6 decking, joints caulked and joined with fiberglass tape, prior to the application of the coating. My questions are 1) what is the best method of leveling those spots which are low? and 2) is it a good idea to glue the plywood to the underlying 2×6 as well as screw it down?
Thanks in advance for any suggestions or ideas.
Replies
Well, first thing is
You don't want a deck to be level!
You wantit to pitch away from thje house a minimum of 1/8" per foot. The existing framing should already have at least that. If not, you need to rip-taper them or shim them up.
The second thing that comes to mind is that 2x6 framing is awfully light for a deck, unless it is very small, but you do not say what the span is. You might need to sister the existing to prevent the whole thing from ending up with a belly in the center that cups and holds water.
And finally, what is your climate?
Not real clear in orginal post
I should have been clearer in my orginal post. The deck slopes 1/4 inch in 12 away from the house. The decking is 2x6 laid flat at a 45 degree angle to the joists (which are on 16 inch centers). The framing is not 2x6, it is appropriately sized 2x and 4x post and beam with spans of less than 6 feet from beam to beam below the joists. The level I am trying to correct is small scale, where an individual or small number of 2x6 deck planks are low so that the overlying plywood would not make contact. I'm basically asking, 1) is shimming necessary (how much gap needs a shim) and if so, what is the best material when the shimming will vary, and: 2) will using an adhesive between the existing deck planks and the new plywood be advisable (would the polyureathane foam adhesive used to attach plywood flooring to the joist serve any gap filling purpose or is it too limited in load bearing)?
Do the shimming necessary to prevent water from pudding on the new solid deck. For minimal - one option would be spray foam adhesive which expands a bit. Then you have to be careful how tight you suck the plywood down with the screws.
Forgot to mention climate
My climate is Southwest Montana, sun, rain, snow, hail, wind, -40 to +100 degrees F.
To level the deck just have folks on the high side hike out a little.