Noisey Trex?????

Shoreline58

I am a commercial GC so my experience with some residential materials is limited. This past summer I had a deck replaced and used Trex for the surface.
I have what I think is a very noisey Trex deck. When I say noisey I mean it! When the temperature drops to 25-15F the deck occasionly makes a sound somewhat akin to a 50 pound log dropping from about twenty feet up. No, I am not kidding. The framing appears fine.

I Googled this issue and came up empty. Is this a simply an expansion/contraction issue?

genecarp

Never heard that level of noise you describe, check the clearances around the perimeter and between pieces, there should be a 1/16===to an 1/8'' to allow for exp and contraction. GMOD also, how was the deck fastened?

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curtis fulton

it could also be shrinkling and the swelling of the decking to cause that does do that in changing of tempertures too, and it also just maybe the framing members moving too with the ground and the fasteners

mike stanislaw

Just finished a 2000 SQ FT deck using Timberrech XLM with there hidden fasteners. When the temp goes down below 27 or so it gives off a cracking sound when walked on. It stops when the temp goes up around 30 or or more. Its not a problem and it really looks great. We think because of the hidden fasteners ice forms between the decking and the joist then once weight is aplied it sends off a cracking sound.

nailkiller1

Are you sure its the deck
Is it screwed or blind fastened

festerized

Check to see if the beams are all crowned up
Take a string ling under the deck from end to end, blocking up each side
Then measure each beam to line.
While your under look for screws that missed the beam or only half imbedded

Outback Inc

If this is a brand new deck and it's going through it's first winter, the noise should diminish as time passes if it's contraction and expansion as I would believe it is. I have built many decks using composites and have found that they do make a lot of noise when they're new. Everything's tightly screwed. Some of the screws may be shearing off. I've seen that in extreme cases. Some types of composites are much worse than others that way. I don't use a lot of Trex so my knowledge of that specific line is limited. In any case, if the deck is new I would assume the most likely cause to be the decking and framing materials going through their first extreme cycle of contraction with the cold temps. Those noises can be quite loud. I wouldn't completely rule out the possibility that it could be something else though.

Shoreline58

Thanks for the input. The deck is framed with 2x8 PT joists 16" O.C. and face screwed with two screws at each joist location. I forgot the brand of screws but they were one of the more popular dual thread types. Crowns are up and no sign of cracks anywhere.

The idea of the occasional screw shearing makes sense and may well be the problem.

mike stanislaw

Shorelone what kind of decking? And what shoreline are you at.?

Outback Inc

What is the span on those 2x8's? Also pressure treated wood is very corrosive to metal. Some decking screw coatings are rated for use with PT wood (ACQ), such as FastenMaster's Trapease screws , but some other screws may not be rated as well against corrosion. It should meet or exceed Hot-dipped galvanizing, and of course stainless would be best.

The one other thing about PT is I believe the strength of the lumber is somewhat reduced, I've seen some information on this, but can't recall the exact particulars. In any case a #2 Doug Fir 2x8 can span further than the typical PT 2x8 which I believe is also more commonly Hem-fir (at least in my part of the Country), meaning less strength to begin with in addition to the PT reduction. This would lead to more movement and flex from loading and may be a contributing factor to what's going on.

Also in PT wood, the screws don't grab as well and longer screws are needed as opposed to standard DF. In my experience anything less than 3" doesn't grab well enough in PT wood and 3 1/2" would be preferable in my opinion. You could take a few out maybe and see if they are starting to corrode at all. I have seen galvanized flashing in direct contact with a PT ledger in a matter of a few months already showing some significant corrosion.

It may also be worth checking to see that your ledger is holding tight to the building and that those fasteners are adequate for the exposure as well as the size. Joists can pull away from the ledger as well and there are ways to build in avoidance of that (hangers don't provide much value with that particular stress issue). Both of these issues could occur at anytime of year though and since we're thinking that this is a cold weather issue, it makes sense in my opinion to address some of those other things first and just check on the ledger, joists, etc, at the same time.

edmontondecks

As Outback mentioned, what is the span of the 2 x 8 joisting, what is beam construction and post locations, how much cantalever?

Anytime I do a composite deck, simply because of the weight issue, I run a minimum 2 x 8 joist 12" o.c.

www.edmontoncustomdecks.com

Pat M

Shoreline58-
I am a representative of Trex and would like to assist in addressing your concern. The best thing we can attribute this to be is the standard shifting and settling of the framework. For example, when you hear noises in your house such as pops and such, which normally happens when it’s really cold or really hot. There is nothing to worry about, as there is nothing structurally wrong with the deck as long as this is built to our installation instructions.
Pat M- Trex Company

foosman

Just finished a TT DB deck (other than railing). The temperature has been fluctutating by 25-30 degrees or more in a day (30s in the AM and 50-60s in the afternoon). Used concealoc fasteners (a.k.a- Tiger Claws). It is not as loud as you described, but definitely noisy initially, crackly-type noise as you walk across it...quieted down significantly after a few days...seems to be settling and going thru expansion/contraction cycles due to the temperature swings and some days is silent. The deck has ~17 ft long boards (24'x14' deck on diagonal), so I expect a bit of expansion and contraction.

Great products. Tough to get longer boards into the concealoc fasteners w/out a helper, but otherwise easy/quick to install. The Desert Bronze is a nice product and happened to get in on a local yard that was clearing out 20' and 16' grooved @ $2.50/ft.

Andy2003

Just finished a rather large TT deck (48'x16') w/ radiance rail and decklites. We used the XLM with conceal loc fasteners. We had the same kind of temperature fluctuations as you were talking about foosman, I don't recall any kind of popping at all. We did have a little bit of crackly noise but it pretty much went away after a few days. We put a healthy gap in the butts of the boards, we strictly used 16' simply for the fact that I don't like to deal with the 20'. Our lumber yard was clearing out a bunch of the grooved and we picked it @2.33/ft. Really nice product and easy to install.