Redeck - which way is better


When it comes to re-decking, I see basically 3 ways. Tear off everything and start over, replace just what is rotted here or there, or re-deck right over the top.

A few random questions.

I assume it’ll always be cheaper to either spot replace or over the top. On a 30 sq roof, at what point is it cheaper for the customer to just have you go over the top - IE, how many bad sheets total where you have to pry them up, cut to fit, etc, where the labor is just too much to make it worth not going over the top?

Is there any problem with going over the top? Can the deck be so bad you have to tear off the old deck and put a new one on?

Is there ever any point where tearing everything off and starting over (say, if that’s the code in FL) is cheaper than spot replacing? I have to check the code again, but I believe there is something in there about at a certain percentage replaced you have to replace all. Hell, I’m not even sure if going over the top is allowed down here.

What’s a fair price per 5/8" ply sheet installed?


It really depends in your situatuon. When replacing rotted sections on 1/2" or thicker plywood I don’t like doing anything smaller than a 24" rip. Thinner than 1/2" plywood like 3/8 normally recommend rechecking.

We never deck over, plywood decks, if you are shooting the shingles down even nails don’t always penetrate the old wavy plywood on the bottom and will pop back up. We regularly deck over non rotted 3/4 and 5/4 plank decks with 1/2" plywood to smooth the deck out and eliminate plank gaps, shooting it to the rafters with 12 d and then nailing shingles with 1 3/4" coils.


We tear off shingles…locate rafters…and screw all decking with 2.5 to 3 inch exterior decking screws. All rot needs removed and replaced before a deck over so dry rot isn’t left behind to attract insects.


Nails are fine but with screws…you always know you hit the rafters. If 2’ oc we usually also run a screw line in between rafters and use a course thread wood screw to pull both sheets together tightly. 30 sq here in n.c. with 1/2" osb top sheet would cost an average around 2500 to 3000.


Looking further at the code, it seems like the only approved solution is replace 5/8 ply with 5/8 ply, I see nowhere where deck overs are allowed in miami dade. Code also says cant be less than 12" rip, must go 2 spans, etc.

Whats a fair price per sheet 5/8 ply remove/install?


I charge100$ per sheet labor and material


In pa we do 3$ sq ft 1/2, 4$ sq ft 5/8, but depends on area labor rates are higher here than in flat.