Deck Joists On Top Of Or Terminate Into Beam - Building & Construction - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 04-12-2013, 08:45 AM   #1
Yardley, PA
 
Join Date: Nov 2012
Posts: 16
Rewards Points: 10
Default

Deck joists on top of or terminate into beam


Hi Guys,

Just finalizing my deck plans now. Will be 18x16 with 18' being the width which will attach to the house.

Planning all 2x10 framing but am running into an issue with height. We have only about 2 feet from grade to the top of the finished deck.

My question is for the joist installation. I'll have 2 beams, and a ledger supporting the deck. If i run the joists over the beams, i'll only have a few inches to set my beam posts. Is that ok? Or would it be better to support the beams approx 14" (bottom of beam to grade) and then terminate joists using joist hangers. I know the cheaper alternative will be to run joists over the beams but i'm more concerned about the right way.

Thanks,

Advertisement

BJohnston is offline   Reply With Quote
Old 04-12-2013, 08:49 AM   #2
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,798
Rewards Points: 712
Default

Deck joists on top of or terminate into beam


Got a picture of the plans?
Why attach it to the house and not make it free standing so there's 0 chance of damage to the home?

Is the decking going to be a minumum of 4" below any door openings.

Advertisement

__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
joecaption is offline   Reply With Quote
Old 04-12-2013, 09:00 AM   #3
Roofmaster
 
Join Date: Oct 2012
Location: Maryland
Posts: 3,669
Rewards Points: 2,096
Default

Deck joists on top of or terminate into beam


You are wasting a heck of a lot of money on joists for no reason if you have two supporting girders. You can still cantilever the joists and locate your girders at 7 and 14 feet. 2 x 8's at 16 inches on center are more than enough.
__________________
" A lot of men build things, and a lot of things fall down "

jagans is offline   Reply With Quote
Old 04-12-2013, 09:02 AM   #4
Yardley, PA
 
Join Date: Nov 2012
Posts: 16
Rewards Points: 10
Default

Deck joists on top of or terminate into beam


So here are the plans as they stand right now, with joists in between the beams.

If i go the route of over the beams, i'll most the last beam row in about a foot and have an overhang. All the loads will still be ok.

Went the attached route because it seems easier. Having to dig and additional 4 8' holes does not sound like fun.

The top of the decking will be 4.5" from door opening.

Let me know what you think.

Thanks.
Attached Files
File Type: pdf 18x16 Plans.pdf (79.5 KB, 52 views)
BJohnston is offline   Reply With Quote
Old 04-12-2013, 09:10 AM   #5
Yardley, PA
 
Join Date: Nov 2012
Posts: 16
Rewards Points: 10
Default

Deck joists on top of or terminate into beam


That was another possibility, so you think i can go down to 2 2x8 for beams and 2x8 for joists and still be ok?
BJohnston is offline   Reply With Quote
Old 04-12-2013, 09:21 AM   #6
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,798
Rewards Points: 712
Default

Deck joists on top of or terminate into beam


Anyone else think there's to many footers?

If you look around on this site and any DIY site you can find dozens of homes needing major repairs from the ledger being attached directly to the side of the house.

Can it be done, sure but why take a chance?
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
joecaption is offline   Reply With Quote
Old 04-12-2013, 09:49 AM   #7
Yardley, PA
 
Join Date: Nov 2012
Posts: 16
Rewards Points: 10
Default

Deck joists on top of or terminate into beam


Water damage? Or Structural? or both?

I think i need the 4 footings, crap clay soil really brings down the load i can carry on each footer. For an 18" tube, the footer will only bear 2,650 psf. I don't think i can get away with 3 footers on the interior, I can on the exterior but will have to move up to 18".


I think i'm going to change everything to 2x8s. That will give me some breathing room to attach the posts.

I'll redesign to have 2x8's on top of beams.
BJohnston is offline   Reply With Quote
Old 04-12-2013, 10:07 AM   #8
Roofmaster
 
Join Date: Oct 2012
Location: Maryland
Posts: 3,669
Rewards Points: 2,096
Default

Deck joists on top of or terminate into beam


Hello, hello, anybody home? If you move the outer girder in 2 feet, your supports will be back under the deck, Your joist span will be cut down by 2 feet, and you will gain the load bearing capacity gained by using cantilever construction. Remember that the dead and live loads on the outboard of the cantilever counteracts any loads on the inside of the cantilever.

I would also check your span ratings for your girders and go with (3) 2 x 8 or three 2 x 10 and not 2 for girders. (2) 2 bys laminated are only 3 inches wide, which is not all that great from a roll standpoint.

You will save a lot on money on framing members and gain height by rethinking this deck.
__________________
" A lot of men build things, and a lot of things fall down "

jagans is offline   Reply With Quote
Old 04-12-2013, 05:18 PM   #9
Member
 
GBrackins's Avatar
 
Join Date: Apr 2012
Location: Fairhaven, Massachusetts
Posts: 2,877
Rewards Points: 2,032
Default

Deck joists on top of or terminate into beam


BJohnston,

excellent advice from joe and jagans. Might want to check out the Prescriptive Residential Wood Deck Construction Guide from the American Wood Council. This is based upon the 2009 International Residential Code. Simple and easy way to figure out spans and sizes of joists and beam, also spacing of supports for beams.

I believe this is the link to the Pennsylvania Uniform Construction Code.

it states that PA uses the 2009 International Residential Code as the basis for the residential code.

a free standing deck have a lot of advantages. as joe stated don't have to worry about issues with the ledger attachment. as jagans said you can cantilever the ends of the joists and reduce the floor joist span between the two beams. using a 3 ply girder may reduce the height of the girder.

depending on your building code (need to verify with building department) a deck this size may not be required to have footings that go below your frost depth. See Section 403.1.4.1 of the 2009 IRC:

R403.1.4 Minimum depth. All exterior footings shall be placed at least 12 inches (305 mm) below the undisturbed ground surface. Where applicable, the depth of footings shall also conform to Sections R403.1.4.1 through R403.1.4.2.
R403.1.4.1 Frost protection.
Except where otherwise protected from frost, foundation walls, piers and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods: 1. Extended below the frost line specified in Table R301.2.(1); 2. Constructing in accordance with Section R403.3; 3. Constructing in accordance with ASCE 32; or 4. Erected on solid rock.

Exceptions:

1. Protection of freestanding accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.
2. Protection of freestanding accessory structures with an area of 400 square feet (37 m2) or less, of other than light-frame construction, with an eave height of 10 feet (3048 mm) or less shall not be required.
3. Decks not supported by a dwelling need not be provided with footings that extend below the frost line.

Many things to think about, hope this helps .....

Advertisement

__________________
Gary

"You get what you pay for, and sometimes free costs more!"
GBrackins is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Deck Staining Nightmare steven994 Painting 6 04-06-2014 10:10 PM
Triple 2x10 beam has twisted WillK Carpentry 11 12-28-2011 12:50 PM
Deck Support Beam temporary fix. george747 Building & Construction 5 10-17-2011 10:41 PM
Where would I purchase metal shims? Vincer Building & Construction 19 05-28-2011 11:46 PM
How to add another support beam under floor joists LOStouten Carpentry 3 11-13-2008 11:55 PM




Top of Page | View New Posts