[RX4640]

I have a existing deck that is old (16+ years). I need to replace 4 or more joists (2x10) that have rotted. The old joists are 9 inch wide, the new are 9 1/4 to 9 1/2 wide. The joist are about 12 feet long, mounted to a plate on the house and sit atop a cross support at the other end.

The problem I am having is the width of the new joist will make the decking sit 1/4 to 1/2 inch above -

Question: should I notch the joist so it sets at the same high as the existing joists? What about the joist "shrinkage" over time? Will i end up with a low spot in the deck over time.

Thaks

 

[Nealtw]

I have a existing deck that is old (16+ years). I need to replace 4 or more joists (2x10) that have rotted. The old joists are 9 inch wide, the new are 9 1/4 to 9 1/2 wide. The joist are about 12 feet long, mounted to a plate on the house and sit atop a cross support at the other end.

The problem I am having is the width of the new joist will make the decking sit 1/4 to 1/2 inch above -

Question: should I notch the joist so it sets at the same high as the existing joists? What about the joist "shrinkage" over time? Will i end up with a low spot in the deck over time.

Thaks

Can you move them around so you are putting the tallest one at one end. They will shrink down to 9 1/4 or less.

 

[RX4640]

my deck is 39 feet wide, the rotten joists are in the middle area.

 

[udraft]

Yes, then notching to level makes sense.

 

[Nealtw]

Yes, then notching to level makes sense.

If you are notching then rip it to size.

 

[Randy Bush]

Lumber anymore for decks is terrible . It is slower , but I joist hangers as I go so the tops are even with the ledger.

 

[jeffnc]

If only the top edges of the joists are rotting, but the ends are solid, you can just sister them with 2x8s (or as little as 2x4s) to get a solid nailing surface. If replacing them and you have a table saw, rip them down a half inch.

 

[RX4640]

Thank you all ! I'll be going with the joist sister with 2x8 and rip to size as needed.

Thanks again for all the great responses

 

[Half-fast eddie]

Thank you all ! I'll be going with the joist sister with 2x8 and rip to size as needed.

Thanks again for all the great responses

That might not work. To do it properly, the new lumber need to be full length … within an inch or two on each end … and properly attached to the old joist. ”properly” means following a prescribed nailing or bolting pattern.