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We bought a brand new house in 2015.

Fall of 2015, we put Thompson's water seal on the top of the deck. I am learning that this was a mistake and it should have been applied to ALL sides of the deck apparently (according to a DIY friend)?

I am not sure if this is what caused it but now after 2 winters, the deck pops and creaks terribly every time we walk on it (of course, maybe not the winter that caused it but last spring it was pretty bad and this spring, even worse).

I noticed also that some of the screws used to fasten the wood to the deck supports are actually going inside the wood (the screw heads seem to be sinking in to the wood).

Maybe the problem is twofold but I also see some moisture buildup on the underside of the deck when I look up at it from the patio.

I read another thread and people said it may be caused by too much movement in the deck (could the screws sinking into the wood cause that)? Another suggested remedy was to remove each board one by one and put glue down on the joists, then replace with 3 1/2" deck screws but I want to get some help from DIYers first.

I'm honestly not sure what type of wood it is by the way, looks like some treated lumber.

How can we fix it? Thanks a lot!

  • Were the screws sunk into the wood when you first got the house? Was the moisture buildup there in 2015? – Harper Jun 22 '17 at 15:31
  • There was for sure no moisture buildup when we moved in. I wish I would have, but I didn't pay much attention to the screws. If I had to guess, I do think they sunk into the wood more since we've been there. – pab Jun 22 '17 at 15:37
  • the only thing that could drive the screws in further would be very intense warping of the wood, which would leave telltale gaps between the wood and the stringer below. If you've ever driven deck screws, you know you don't hand drive them, you put a screwdriver bit in a power drill. It is very fast and is extremely difficult to control the screw depth with any precision. They err on the side of not leaving any sticking up. Me, I switched to a speed wrench for speed and precision. – Harper Jun 22 '17 at 16:06
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    I have never glued a deck down but I have gone back and tightened the screws, I love torx or star head screws they are the best for not stripping the heads out. Also I have never sealed the bottom of the boards. I agree with Harper a 1/4" impact or power driver is the best way to screw down and control the depth. – Ed Beal Oct 24 '17 at 19:23
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pab,

When new pressure treated wood is used for projects, it is fine when it's fresh. However, over time the pressure treated wood shrinks around the fastners as it dries and cures. It appears as though they are are sinking, but actually the wood raises sinse it's not as snug any longer. My suggestion would be to replace your existing screws with a size bigger to fill the void around screws/nails etc.I would also check to see if possible, that no fastners have missed any of the joist during installation.

As far as the the water water sealer goes, you want to put it over every crack and cranny of the deck that you can possibly get to. A thick napped roller or sprayer will help with application.

The moisture build up could have been avoided if done properly during the deck install. It is code is some areas to put down lanscape fabric or 4-6 mil black or clear plastic followed by up to 4" of stone that is 1" down to pea gravel size. This controls weeds, mold, and allows for drainage. This may not be feasable now that the deck is built, but I would consider pulling some boards randomly, and trench the water away from under the deck. Good luck!

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Movement and creaking is caused by the contractor using the standard 5/4" deck wood. Next time use "two by" lumber , as 2 X 6. it is 1.5 in. thick instead of 1.25 in. thick. That thickness give twice the strength, twice the stiffness and twice the life. My deck is 20 years old , been stained/ sealed 2 or 3 times. This summer I replaced about 2 % that did not look good. The only problem is the steel deck screws are rusting away . I am replacing them as needed with stainless screws. I recommend not sinking the heads as your contractor did as the hole holds water = rust.

  • proper supporting substructure provides the necessary rigidity. no reason not to use treater 5/4 decking. – aaron Nov 15 '18 at 18:07
  • My point is not that 5/4 won't work ; it is just not economical. The subdivision has replaced a large 5/4 deck twice ( and looks bad again) during the same period my deck is still good. – blacksmith37 Nov 16 '18 at 15:47
  • did they take the usual and necessary steps to maintain it with protective deck stain? – aaron Nov 16 '18 at 16:15
  • I coated mine no more than 3 times in 20 years. I think the HOA (Home owners Association) coats theirs once when it is installed. The people at the HOA don't care how long it lasts and the contractor does not want it to last too long. – blacksmith37 Nov 17 '18 at 20:26
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Some responses have noted that the deck material ie 5/4”, Some refer to it as pressure treated, etc. I don’t know how they know this...here are some ideas:

So, to solve the “popping and creaking”, we should confirm 1) material (species) used, 2) thickness/span, 3) number of fasteners per support, 4) shape of board, 5) stability (rigidity),

1) Some species will shrink more than others. However, shrinkage does not lead to popping and creaking unless it was so wet that it shrunk across grain and lifted it off its supports. Then, when stepped on, it would “move” on the fastener. I doubt the boards could shrink enough to cause this phenomenon.

2) If the boards are over stressed (the boards are spanning too far for their thickness), then you could hear a creaking. However, you’d be complaining about the boards being too springy. As a rule of thumb, most grades and species would be fine with: 3/4” thick for 16” span; 5/4” thickness for 20” span; and 1 1/2” for 3’ span. Do your boards exceed these spans?

3) Each board should have 2 fasteners at each support. If not, it could twist and bow causing the popping and creaking sound when walked on. Are there 2 fasteners at each support?

4) Most exterior decks are surfaced 4 sides and not T&G. If T&G, it could cause creaking in an exterior atmosphere.

5) When decks are not rigid, they move causing the fasteners to loosen. Does the deck platform tend to move easily?New decks are now required to have anchors located along the house that keeps it secured to the house. Is there any diagonal bracing under the deck?

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