Thread: How necessary are moisture meters

Originally Posted by nifty

Its interesting you say they were laid one summer and then shrank like buggery the next. First question, what were the joists made from?

New Jarrah joists on Oregon glulam beams - When I say they shrank next summer - they shrank a little during the whole year but by the middle of next summer you could pass a sheet of paper straight down between the tongue and groove!

Nifty, thanks for the reply. Looking in Forest Trees of Australia and A Field Guide to Australian Trees, Pterocarpus macrocarpus is not even mentioned. I suspect that it may be Dysoxylum fraserianum - Rosewood (Rose Mahogany). Are you able to help with this?

Bob R, according to my bible here, Rose mahogany *(Dysoxylum frasernium) has an
SG of .6

Bob L, new jarrah joists as in green and lets say they are not exposed underneath creating two atmospheric pressures on your floor from above and below, the joists should and will shrink more from the floor side because as a rule of thumb, more warmth from the top plus weight your joists may well have only shrunk from one side. Had this same thing happen when i was a carpenter on a pine t&g floor on jarrah joists on a second story

Thanks Nifty - loks like I was close. BTW, what is your bible.

It came with my flash moisture meter. It has alot of the yankee timbers, euro timbers and alot of ours in it, if you like i can take copies of it and fax em or email to you if you like if that would help

email would be good thanks. Are we able to attach to a PM here or do you need my email address.

I will see what my fragile little mind can handle and get back to you Bob R

Nifty, have any luck. Is there a web site you can point me at.

Sorry mate, forgot all about it. Will get onto it tonight

I have two little $20 resistance meters that seem to be as consistant as my mates $300- $500 unit.
So far I haven't had any trouble. With solid wood its almost always going to move at some time or other so you still have to alow for movement either shrinkage or expansion anyway. I only use them to weed out anything thats not consistant with the bulk of the timber in the job. Oh yes I would like a spiffy one but I have other things I need more
Yes, I do think they necessary but I haven't had to spend much to meet my needs.

I have a German Gann H25 pin style meter here that I no longer require now the mill is gone that I would be open to offers on if anyone wants it.