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jgates
floor joists

I have a 1850 old house with joists made out of logs. I sistered the beams in july of last year when they were swelled with moisture. My mistake, anyway winter time the beams shrank and the bouncing came back. Now it is summertime and the bounce is gone. Can I seal these beams with a waterproofer to keep the moisture in? Any ideas?

ed21
Re: floor joists

It might be better to make sure the sistered joists remain in contact with the original joists. This could be done with through or lag bolts so the new joists & existing act as one unit. Some shimming may be required to keep things tight.

keith3267
Re: floor joists

Make sure your sistered joists are glued (constriction adhesive) and nailed or lag bolted (through bolts also work) to the log beams, but you might have been better off using blocking or bridging between the log beams. This is the more traditional way of removing the bounce.

jgates
Re: floor joists

Did every thing mentioned but in winter time humidity went to 10 percent, making the beams pull away from the floor. Should I resister the beams in winter? afraid when summer comes and the beams expand - may not be pretty.

keith3267
Re: floor joists

Now that it is summer, if the beams have expanded, you can spray them with ethylene glycol antifreeze. You need the full strength antifreeze, not the 50/50. The antifreeze will displace the water in the beams. It is best done when the beam has some moisture as a dry beam will reject the antifreeze, a moist beam will draw it in.

The antifreeze will not evaporate as much as the water so the beam should not shrink. In addition, the antifreeze is an anti-microbial so it will preserve the beam and eliminate any rot, mold or mildew. It also discourages insects like termites and ants.

Caution, ethylene glycol is very toxic if ingested. About 1 oz is fatal to adults. Wear a mask while spraying and do not allow children in the basement while doing this. Once the mist from spraying has settled, then it is safe to be around. You can also apply it with a paint brush if you like, less mist that way. It is not a skin absorber as far as I know so it should be safe to handle, mechanics handle it all the time.

jgates
Re: floor joists

Thank you, I will try this

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