Decking Perpendicular to House?
#1
I'm planning a deck that will span the 40' length of the back of my house, and extend 14' out from the house. To avoid all the joints in the decking, can I construct the frame so that the decking runs perpendicular to the back of the house? That is, simply by decking in 14' lengths, and have them run straight out from the back of the house.
Are there structural reasons NOT to do this? If not, are there additional structural considerations?
Are there structural reasons NOT to do this? If not, are there additional structural considerations?
#2
ccase,
I think that 14' is a good call. 14' lumber is NOT a standard multiple 4' length, and therefore it is not as expensive as most other lumber. It gets out there, but it does not cost as much as say, 16' lumber, that has to be cut off. Go for it. Good Luck!
I think that 14' is a good call. 14' lumber is NOT a standard multiple 4' length, and therefore it is not as expensive as most other lumber. It gets out there, but it does not cost as much as say, 16' lumber, that has to be cut off. Go for it. Good Luck!
#3
I've built a few decks this way. Some folks insist on it.
The 40' length can be spanned using 14' 2x8 joists overlapped at the joints. You'll also need to use girders under your joists that will run the same direction as your decking.
Put the girders at midpoint between the overlaps and also at the overlaps. I'd put posts between the girders at the 7' mark.
More than a Carpenter
http://www.carpenter.cjb.net
The 40' length can be spanned using 14' 2x8 joists overlapped at the joints. You'll also need to use girders under your joists that will run the same direction as your decking.
Put the girders at midpoint between the overlaps and also at the overlaps. I'd put posts between the girders at the 7' mark.
More than a Carpenter
http://www.carpenter.cjb.net
#5
Couple questions in response:
1. Would you half-lap the joist joints, so there'd be a single, uninterrupted joist the full 40' span, or simply bolt them to each other without half-lapping?
2. How much overlap for the joists?
3. It sounds like you're saying that I want girders every 7' along the length of the house. Or are you saying alternate girders and posts on 7' intervals?
Thanks
1. Would you half-lap the joist joints, so there'd be a single, uninterrupted joist the full 40' span, or simply bolt them to each other without half-lapping?
2. How much overlap for the joists?
3. It sounds like you're saying that I want girders every 7' along the length of the house. Or are you saying alternate girders and posts on 7' intervals?
Thanks
quote:<HR>Originally posted by More than a Carpenter:
I've built a few decks this way. Some folks insist on it.
The 40' length can be spanned using 14' 2x8 joists overlapped at the joints. You'll also need to use girders under your joists that will run the same direction as your decking.
Put the girders at midpoint between the overlaps and also at the overlaps. I'd put posts between the girders at the 7' mark.
More than a Carpenter
http://www.carpenter.cjb.net <HR>
#6
7 feet for joist girders is kind of stretching it. I ususally put mine every 5 feet. It really helps keep the bounce out of the deck, especially a continous deck like yours. I lap my joists at least one foot. Of course at the lap there is a 1 1/2" offset. that is ok. It is better then a splice.
#7
If you were to use 10' joists then Jack would be right on. I am refering to using 14' joists.
Girders every +/- 7' (1/2 way between posts) with a post at each corner and +/- 13' between the others.
Three 14' boards is 42' long. You deck is 40'. Do the math and see where the supports need to be.
You might strongly consider putting a post at every girder. Run them all the way from the footing to the handrail. The ones under the deck get cut off flush or just short of the the top of the joist. Bolt the girders stradling the posts.
The joist do get the 1 1/2" offset and then back on the next one.
Use a cleat that attaches to your band board/ledger/rim joist to also attach the inside of the girders.
More than a Carpenter
http://www.carpenter.cjb.net
Girders every +/- 7' (1/2 way between posts) with a post at each corner and +/- 13' between the others.
Three 14' boards is 42' long. You deck is 40'. Do the math and see where the supports need to be.
You might strongly consider putting a post at every girder. Run them all the way from the footing to the handrail. The ones under the deck get cut off flush or just short of the the top of the joist. Bolt the girders stradling the posts.
The joist do get the 1 1/2" offset and then back on the next one.
Use a cleat that attaches to your band board/ledger/rim joist to also attach the inside of the girders.
More than a Carpenter
http://www.carpenter.cjb.net
#8
See what happens -- you ask 3 different carpenters how to build a deck and you get 3 different answers!! Nothing wrong with the other 2, but a third way to join the joists (albeit more work), would be to mortise out the top of the posts so your joist sits in the mortise and through bolt everything. Where 2 joists meet on a post, use twice as many bolts. (Same number per joist, but at the joints, you have twice as many joists!)