Please help me figure out what's causing the creaks in my DIY loft.

November 30, 2006 6:37 AM

Please help me figure out what's causing the creaks in my DIY loft

Three months ago, I constructed a loft out of 2"x6" and 2"x8" lumber, 5/8" plywood, metal joists, carriage bolts, and decking screws. The day it was built, the loft held our queen sized bed and the weight of three people (500 lbs) without any creaks. Now, the loft creaks every time we get into it.

There are no obvious signs of stress. When people walk up the similarly constructed stairs, there are no signs of buckling. When someone stands on the loft, even if they stand between the floor supports, there are no signs buckling. Visible signs aside, the audible creak seems to be getting worse.

The temperature has dropped enough since September 1 that we run our heat now. My best, but uneducated, guess is that the heat and indoors placement of the wood has caused the wood to dry out over time, which in turn causes the creak to get worse.

Testing shows that the creaky noises come from the junction of the joists, wood and decking screws. I'm trying to determine three things:

1) What's the likely cause of the creaking noise?
2) Is the noise indicative of potential structural failure?
3) What can be done to reduce the noise?

posted by sequential to home & garden (9 answers total)

Creaking could easily be caused by the drying of the wood, or the temperature itself shrinking or expanding the wood. I am doubtful that it is an indication of structural failure. One solution you could implement is rebolting the wood with rubber washers/grommets to keep the connection tight, and thus avoid squeeks.
posted by torpark at 6:49 AM on November 30, 2006

Does this thing need to be dissassembleable? If not pepper it with woodscrews through the plywood into the supports at 6" intervals, run a bead of "Liqud Nails" adhesive along all the concave joints. Get some wood shingles and drive them into any accessable gaps, trimming off what can't be hammered in. A little adhesive in the crack first is ideal. Is the thing structurally solid? A well placed diagonal tensor consisting of nice solid eye bolts on opposing members and connected with a steel cable tightened with a turnbuckle should do it.
posted by StickyCarpet at 7:00 AM on November 30, 2006

A creak is caused, 99% of the time, by a nail that has loosened and is rubbing against the wood beams/joists when you put weight on the loft. If it's carpeted, you'd be wise to check out Squeeeeek No More. I've used this kit in my house (a set of screws and a special jig for your power driver that lets you set in a screw through your carpet, then break off the shaft below carpet level), and it works great.
posted by Merdryn at 7:12 AM on November 30, 2006

I think torpark is right - I once built a loft in a studio apartment using carriage bolts, and it creaked like mad as the dry wood twisted around the smooth bolts. Taking out the bolts and reassembling with rubber washers might help, but in my case, I just lived with it for a couple years.
posted by M.C. Lo-Carb! at 7:15 AM on November 30, 2006

Does this thing need to be dissassembleable?

Unfortunately, the answer is yes. If I can't sell the loft to the next tenant, I have to disassemble it and take it with me.

pepper it with woodscrews

Excuse my ignorance, but are wood screws different than deck screws? The plywood is currently held to the frame with 2" deck screws.

A well placed diagonal tensor consisting of nice solid eye bolts on opposing members and connected with a steel cable tightened with a turnbuckle should do it.

I like that idea so much better than the 12' boards I have running diagonally across three sides of my loft.

I once built a loft in a studio apartment using carriage bolts

There are 16 3/8"x4.5" carriage bolts that are used only to hold the frame to the posts providing the vertical support. Though they creak without the cross bracing, they don't appear to be the source of the creaking now.
posted by sequential at 7:22 AM on November 30, 2006

Every loft I've built has ended up creaky. None have had any apparent structural problems [thick plywood, 2x6 frame/supports and 4x4 legs, etc.]. I doubt you're in for any kind of catastrophic failure. In my lofts, the creaks usually seem to be associated with the joints, particularly the ones with carriage bolts - even with supports, there may be just enough give for a little motion, causing the creaking. Might be because of the wood drying out indoors, or expanding with heat; might be because the bed has settled a little bit after use.

You don't need huge 12' cross-braces - smaller diagonal cross-braces [a few feet long, at most] from each leg to both of the nearby sides of the loft-bed leave the underside of the loft more accessible. I'm not entirely clear on whether i'm picturing StickyCarpet's steel cable scheme correctly - wouldn't it pull the legs of the loft inwards, in comparison to 2x4s which, being rigid, prevent the legs from moving in _or_ out? Anyways, consider jamming little wood triangles [like doorstops] into any big gaps at joints. I've never tried switching to rubber washers, so I can't vouch for that, but I'd advise against the "Liquid Nails" - if you ever need to disassemble the loft, you'll hate yourself. [2" deck screws should be entirely adequate to keep the plywood in place.]
posted by ubersturm at 7:42 AM on November 30, 2006

Creaking is caused by wood flexing or rubbing against each other. If you bolt it together rather than use woodscrews or deckscrews, you can keep it much tighter. If it held together very tightly there is very little chance of creaking from flexure. You can try tightening all of the screws but screws don't typically hold as tight as bolts mostly because it is harder to get as much torque on them without the screws snapping.
posted by JJ86 at 8:25 AM on November 30, 2006

Can you get someone with sensitive hearing to identify the source of the squeak or does it change?

I've always heard the trick of sprinkling sawdust or talcum powder on a hardwood floor and brushing it into the cracks can stop creaks. Maybe worth sprinkling some into the joints of your loft?
posted by Rock Steady at 11:06 AM on November 30, 2006

I'm with Rock Steady. It's a simple matter of lubrication.

Reinstall the mechanical fasteners after dusting them with Talcum powder or a light rubbing of soap.
posted by friezer at 6:19 AM on December 1, 2006