[rongrzywacz]

I have an old deck built about 25 yrs ago with 2x6's over 24" spaced (2x10) pressure treated joists. I would like to switch to a trex type deck using 1x4" boards which require the deck joists to be on a minimum of 16" centers.
( There is a trex 2x6 deck board, but they are too expensive)
If i were to add an additional joist between the current 24" spaced decking will the decking look wavy over time as the new pressure treated joists shrink?
Any other options?

Thanks for any help!
Ron G

 

[Half-fast eddie]

If you have time, have the new joists delivered, lay them out in the yard, not stacked, and let them get sunshine for a week. Most of the moisture will bake off.

 

[Nealtw]

Just don't do the side nails in the hangers, so when dry you can drive a shim under them and add the nails.
New treated is not like your old, add joist tape to all the joist but mostly the new ones need it .
I would want them in and held in place while they are wet.

 

[HotRodx10]

If you have time, have the new joists delivered, lay them out in the yard, not stacked, and let them get sunshine for a week. Most of the moisture will bake off.

Oh gawd, don't do that! They'll look like hockey sticks. I agree with letting them dry, but not in the sun. Put them inside a garage or someplace where they can dry evenly. You may have to clamp them to hold them straight while they dry, anyway.

 

[Half-fast eddie]

If you put them in the garage it will take twice as long to dry. If you clamp them together, the ones in the middle won’t have enough surface exposed to dry properly. Let them dry, cut to size, install and add blocking.

Bigger question is … why does the Old Sage Neal say to install wet?

 

[Nealtw]

If you put them in the garage it will take twice as long to dry. If you clamp them together, the ones in the middle won’t have enough surface exposed to dry properly. Let them dry, cut to size, install and add blocking.

Bigger question is … why does the Old Sage Neal say to install wet?

When you build with wet lumber you can bend and twist to where ever you want it. We build houses with wet 2x4s for the wall plates, August lumber is dry and it is just a fight because it comes pre bent and twisted and everything is a fight.
Except for studs wet construction is much easier.

 

[HotRodx10]

If you put them in the garage it will take twice as long to dry.

Probably, but at least they have a chance of staying somewhat straight. Out in the sun, one side dries much quicker, and they usually warp beyond recognition. BTDT; wasted alot of money.

If you clamp them together, the ones in the middle won’t have enough surface exposed to dry properly.

I clamp them down with cribbing (short chunks of 2x3) between each row at 3 to 5 places (depending on the length of the joists), and then clamp the whole stack with bar clamps. So, what I did is lay out 2 or 3 boards (2 for 2x10s), side by side over a couple sawhorses, lay 2x3 pieces, slightly longer than the width of the boards together (so, about 20" for 2 2x10s), across the boards at 3-5 locations along the length of the joists; add another layer of joists and another layer of 2x3s until you have all the joists, or the stack gets unmanageably high. Hold a 2x3 under the bottom row of joists and clamp the top 2x3 to the bottom with bar clamps on both sides; repeat at the other cribbing locations.

Bigger question is … why does the Old Sage Neal say to install wet?

If you hang the PT joists as soon as you get home with them, and screw the decking down right away, the joists are locked in position (and mostly out of the sun). Then all you worry about is them bowing up or down., which isn't as common.

 

[rongrzywacz_2246]

Someone suggested Kiln Dried pressure treated lumber. Haven't seen this before. Is it expensive?