Will be installing 5/8" solid bamboo over 5/8" TG subfloor.
13" trusses as joists, spanning +/- 18 ft, support by 2 beams over 1/2 of the floor size (where staircase is), one beam over the other half.

1. Leveling question. One of the beam is about 3/4" higher on one end than the other beam, resulting in a hump (0 to 5/8") that has the subfloor out of level over an area of approx. 4ft x 12 ft.
after reading various posts on removing sublfoor + plane down vs using asphalt shingles & felt : would results from one solution to the other be very different ?

2. Will my floor feel solid enough given the joist & subfloor & bamboo specs ?

3. Bought a stapler (equiv. Bostich MIIIFS). bought 1-3/4" 15.5 gauge 1/2 crown staples: is this the adequate size given the material specs ? Are there quality differences in the various staple brands ?

4. location is close to Vermont border on Quebec side: what moisture difference between subfloor & prefinished bamboo flooring is acceptable : 2% ? What maximum moisture content should the bamboo have ?

5. Would 8" spacing between staples be satisfactory, or should it be closer ?

thanks in advance for any reply.
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Florian

1) 3/4" is quite a bit to shim and feather out. I'd probably go with the subfloor removal and planing method. If done properly, this should result in a superior job. One thing you may want to do is add some lumber to the sides of those trusses you have planed down, just to ensure they are still stiff enough. Generally, truss manufacturers and engineers do not want trusses cut or changed. But it can safely be done if you compensate for any wood removal by adding more wood alongside.
3) I think there is a quality difference in staples. The generic brands may jam or break more often. Use what the tool manufacturer recommends. 1&3/4" length is long enough for 5/8" flooring.
4) 2% is best, 4% variance is probably acceptable. Always refer to manufacturer's recommendations. A pin style moisture meter is required to answer your question. You measure the current subfloor MC and it says 10%. That means if your flooring is between 8 to 12% MC, then it is acceptable to lay the flooring. However, being that we are in the heating season, I should expect the flooring, after some acclimation, to register much lower, at around 6 to 7% MC. If it was higher than the subfloor, I would allow it to acclimate and dry out more.
5) 8" OC for nailing should be fine. Always refer to the manufacturer's recommendations.

thanks a lot Gary.

Actually, the lumber pieces I will add on the side of the trusses will help me to establish the level line to which I will sand down.

will try the brand of staples I already have. If they jam too much will go for the Bostitch ones.

The plates that came with the stapler are either for 1/2" or 3/4" flooring. I am told the 1/2" should be good for the 5/8" bamboo. Do you believe I will have to shim it (adding cardboard or ?
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Florian

Yes, play with the shims, until you get the right. Roofing felt works good as shim material too.

The subfloor has different measures depending on the location:
1) the rooms towards the North side are from 12% to 16%, according to 8-10 measurements at different locations

2) the rooms toward the South have readings between 6% to 11%

3) I have measured a couple bamboo planks (the planks had been taken out of the boxes over a month ago): 7% to 9%.
But most of the bamboo are still in the unopened boxes, as is advised by the manufacturer (written on the box).

Please give me your comments about whether the differences are normal (1) vs 2), and what to do if the bamboo in the boxes read higher than 9%.

thanks in advance.
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Florian

Are you refering to moisture meter readings? If so, that higher reading is cause for concern. You will need to go under there and see what's going on. Damp earth? Poor drainage? What?

Actually the subfloor is on a second floor over cellulose (dry blown) insulated ceiling, and for first floor it is over a heated basement (slab had been poured over a year ago, moisture in basement seems no problem.
Rel. humidity on first floor is 50% and on second floor 40-45%.

1) on second floor, subfloor MC reads average 15% on the North side rooms, 11-12% on South side (4 pin meter). However, the solid bamboo planks that were in the sealed boxes (plastic wrapped), were reading on average 4%. The boxes had been stacked in the room for over a month, BUT UNOPENED as was advised on the packaging to let acclimatize at least 72 hrs unopened (!!?). The few planks that had been taken out of the boxes were reading 11% on avge.

O) is it possible that the readings for the bamboo are inaccurate given that the pins only get in the bamboo by 1/16" or maybe 3/32" ?

A) How much of a problem will I have if I install the bamboo now ?

B) What can I do to increase the bamboo's Humidity level and reduce the subfloor one at the same time ?

C) For how long (on average) would I have to let the bamboo stay in the 67 degree heated room with boxes open ?

Any other suggestions ?
thanks in advance
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Florian

Any chance somebody would help answer my last questions ?
Would be very much appreciated !

Florian

I would open the cartons, to allow it to properly acclimate to your ambient conditions, unless this is a glueless floating installation and the T&G might be effected in dimensions if you allow it to gain moisture, making it difficult to get together.

I would be concerned about the 15% reading your getting, and... NO!!!! 1/16 to 3/32 is not enough pin depth. You may be reading topical moisture where a bead of your sweat hit the subfloor. LOL!!

Can't tell you how much problems you'll have. I'm not there to see it for myself.

Thanks for the reply.
I am stapling solid bamboo planks (3-1/4" T&G)

It is not the subfloor I meant for the 1/16" pin "penetration, but the bamboo, which is much harder to get the 4 pins in..
The pins get 3/16" into the subfloor, and my readings are pretty homogenuous within a room, so I guess (?!) they must be pretty accurate, even if I might have to apply an offset / correction factor, which by the way the manufacturer of the meter does not know / have...

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Florian