Can I Stack A New Header On Top Of An Existing One? - Building & Construction - DIY Chatroom Home Improvement Forum
Advertisement


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

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

Like Tree1Likes
  • 1 Post By seephor
Reply
 
Thread Tools
Display Modes
Old 05-08-2019, 02:32 AM   #1
Member
 
Join Date: Mar 2014
Location: Los Angeles, CA
Posts: 159
Rewards Points: 253
Default

Can I stack a new header on top of an existing one?


I have a 16' garage door opening that's not a standard height of 7'. It's about 4 to 5 inches short of 7'. The existing header is a 4x12x16 and it's a load bearing wall (holds half of the roof above). The existing header has also sagged a good 1" in the center over the years.

What I'm thinking of doing is frame up a temporary wall on the inside and outside of the garage to hold the roof, Remove the cripples above the existing 4x12, glue up two 2x10's with a 1/2 ply, place it on top of the existing header, install new cripples then finally cut the 4-5" I need out of the existing header.

Three reasons I want to do this instead of removing the existing header completely and installing a new one. One, the exterior siding is stucco. It's going to difficult to remove the header without damaging the stucco. Two, I figure the new double 2x10 sandwich on top of the existing header would only make it stronger and less prone to sagging over time. I'm going to have a header that's close to 16" tall with both of them stacked after cutting the existing header. And three, I don't have to touch the existing framing like installing new jack or king studs again avoiding any damage to the stucco.

Any potential issues I should be concerned about here? I will tie the two headers together with metal strapping as well. Thanks!

Last edited by seephor; 05-08-2019 at 02:41 AM.
seephor is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-08-2019, 03:05 AM   #2
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,018
Rewards Points: 11,922
Default

Re: Can I stack a new header on top of an existing one?


I don't think you can count on the cut beam for anything, the upper will be holding the lower on up. Have you got room for the same size or more as what you have now.



Or if you cut the stucco at the new height and the sheeting at the new height You might be able to get a recip saw blade between the sheeting and the header from above and below and take it out. Or pre cut the cripples above so you can just raise it up and put blocks on the jack studs. Better would be to turn it over and make the sag a crown.
__________________
Do not use flat bottom gables with scissor trusses.

Last edited by Nealtw; 05-08-2019 at 03:07 AM.
Nealtw is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-08-2019, 03:35 AM   #3
Member
 
Join Date: Mar 2014
Location: Los Angeles, CA
Posts: 159
Rewards Points: 253
Default

Re: Can I stack a new header on top of an existing one?


Quote:
Originally Posted by Nealtw View Post
I don't think you can count on the cut beam for anything, the upper will be holding the lower on up. Have you got room for the same size or more as what you have now.



Or if you cut the stucco at the new height and the sheeting at the new height You might be able to get a recip saw blade between the sheeting and the header from above and below and take it out. Or pre cut the cripples above so you can just raise it up and put blocks on the jack studs. Better would be to turn it over and make the sag a crown.
Thanks for the advice. If I'm going to remove the existing header, I will install a LVL and call it a day. The reason I don't want to touch the existing framing as much as possible is again due to stucco siding and in the 1960's here, they didn't use any plywood sheathing, It's just paper and lath stretched over the framing and the mud pressed into the lath. If I remove the existing header and cripples, the stucco will no longer have any structural support. I figure the existing header even though it's cut 5", will serve to support the stucco and the new header above will support the roof. I have a good 16" of space above the existing header so I can also use double 2x12s with 1/2" ply if I want to.
seephor is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-08-2019, 06:26 AM   #4
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,018
Rewards Points: 11,922
Default

Re: Can I stack a new header on top of an existing one?


So you only want people to agree with you then.
__________________
Do not use flat bottom gables with scissor trusses.
Nealtw is online now   Reply With Quote
Old 05-08-2019, 10:23 AM   #5
Hammered Thumb
 
Join Date: Dec 2018
Location: SuburbanIL
Posts: 546
Rewards Points: 1,090
Default

Re: Can I stack a new header on top of an existing one?


If you are going to the trouble to put in a new header, why wouldn't you go with a LAM to begin with? You'll have sag with the 2x10s over 16'.

Ripping 5" off the bottom of the existing 4x12, I would think that would then have a hard time holding itself up and sag even more. If you are going to "hang" it off the header above then that needs to be accounted for.

In general, you cannot lay a separate beam on top of another and then add each individual carrying capacity to get a resulting overall load capacity for what's above them. Each beam will have its own moment (twisting action). Any mechanical connection between the two would have to account for that. And the height of the wall above/below the header will determine lateral loads as well.

And this is not even getting into seismic reqmts you have to deal with in LA.
3onthetree is online now   Reply With Quote
Old 05-08-2019, 10:46 AM   #6
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,084
Rewards Points: 22,526
Blog Entries: 11
Default

Re: Can I stack a new header on top of an existing one?


If the four 2x12s sagged what makes you think two 2x10 won't sag? Sounds like your best option might be a steel beam. An engineer will need to spec it for you. Then you can cut the 2x12s.
joed is offline   Reply With Quote
Old 05-08-2019, 11:49 AM   #7
Member
 
Join Date: Mar 2014
Location: Los Angeles, CA
Posts: 159
Rewards Points: 253
Default


Quote:
Originally Posted by joed View Post
If the four 2x12s sagged what makes you think two 2x10 won't sag? Sounds like your best option might be a steel beam. An engineer will need to spec it for you. Then you can cut the 2x12s.

The existing header is a single 4x12 that has sagged over 60 years. I have 16” of space above the header so I can sandwich 2 2x12s with 1/2 cdx using glue and correct nailing pattern to make my own header. If im not mistaken the laminated 2x12s with ply can be stronger than a single 4x12 so I figure if the house was originally engineered with the 4-by header, adding a stronger header would only over-engineer it unless there’s something I’m missing. The span is not changing here, only the height.
seephor is offline   Reply With Quote
Old 05-08-2019, 11:56 AM   #8
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 22,018
Rewards Points: 11,922
Default

Re: Can I stack a new header on top of an existing one?


Quote:
Originally Posted by seephor View Post
The existing header is a single 4x12 that has sagged over 60 years. I have 16Ē of space above the header so I can sandwich 2 2x12s with 1/2 cdx using glue and correct nailing pattern to make my own header. If im not mistaken the laminated 2x12s with ply can be stronger than a single 4x12 so I figure if the house was originally engineered with the 4-by header, adding a stronger header would only over-engineer it unless thereís something Iím missing. The span is not changing here, only the height.
Depending on the size and loads on the roof a 3 ply 2x12 is often the starting point. No glue or plywood just 4 3" nails every 16"
__________________
Do not use flat bottom gables with scissor trusses.
Nealtw is online now   Reply With Quote
Old 05-08-2019, 12:08 PM   #9
Hammered Thumb
 
Join Date: Dec 2018
Location: SuburbanIL
Posts: 546
Rewards Points: 1,090
Default

Re: Can I stack a new header on top of an existing one?


Quote:
Originally Posted by seephor View Post
If im not mistaken the laminated 2x12s with ply can be stronger than a single 4x12 so I figure if the house was originally engineered with the 4-by header, adding a stronger header would only over-engineer it unless there’s something I’m missing.
Yes you are. See post #5. You are essentially eliminating the 4x12. You are starting from scratch. And be careful with the word "laminate." It can be a structural property like in a glu-lam, which is different than the act of nailing (2) 2x's together.
3onthetree is online now   Reply With Quote
Old 05-08-2019, 12:27 PM   #10
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,084
Rewards Points: 22,526
Blog Entries: 11
Default

Re: Can I stack a new header on top of an existing one?


You have 16" of space so there should be something that will work for you. I would suggest a large gluelam. The lumber yard should be able to size it for you and order it. However I am not an engineer to tell you what you need.
I would suggest you consult one to be sure your loads will be carried properly.
joed is offline   Reply With Quote
Old 05-08-2019, 12:55 PM   #11
Member
 
Join Date: Mar 2014
Location: Los Angeles, CA
Posts: 159
Rewards Points: 253
Default

Re: Can I stack a new header on top of an existing one?


Quote:
Originally Posted by Nealtw View Post
Depending on the size and loads on the roof a 3 ply 2x12 is often the starting point. No glue or plywood just 4 3" nails every 16"
Thanks for this info. I think I have enough information to make a decision.
Nealtw likes this.
seephor is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply



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
Use Existing LVL as Door Header? nobbyv Carpentry 13 12-03-2018 04:53 PM
How to find Header Size of an Existing Window hidytidy Building & Construction 17 09-06-2017 08:03 PM
1950s remodel-New Ducts or repair existing? Dtrain HVAC 6 04-02-2013 07:29 AM
Pergola over existing deck cpfullback Building & Construction 0 08-04-2011 11:36 AM
Raise header of house wall plus add more header capslock Building & Construction 22 02-01-2010 09:13 PM




Top of Page | View New Posts