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Header needed for alcove install?

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http://boards.diynetwork.com/eve/forums/a/tpc/f/9221916776/m/1353913297

Dec 30, 2013, 01:42 PM
Mike B83
Header needed for alcove install?
Hello,

I am new to this site and this is my first post. I need help with an alcove I am going to be opening up, and making bigger.

I currently have a gas fireplace which I am going to remove and install a free standing wood stove in its place.

The fireplace framed into the south exterior wall of my house in an alcove with shoots 24" out of the house. The alcove is 96" wide, 24" deep and 88" tall.

There are two openings, one on each side of the fireplace with windows on each side. The center of the alcove where the NG fireplace is, has drywall and 2X4 framing coming down through the hearth to the floor, (I think there are 2 studs coming down as that's all I could find with my stud finder).

What my plan is, is to remove the fireplace, the wall around it, and the 2X4 framing to make the alcove a true alcove all the way open 96" wide, 24" deep, and 88" tall. Then I would extend then hearth another 14" to give me the required hearth protection for the stove I want to install.

My question is, once I remove the wall and fireplace and its open do I need to put a header along the top of the ceiling now? The ceiling for the alcove will be even with the ceiling where the window openings are now.

This wall has an engineered truss running right there and I think the top of the alcove ceiling is the bottom of the truss as it runs east/west.

Here are some pictures.

Thanks for the help!!!!


Dec 30, 2013, 01:43 PM
Mike B83
Here are more pictures

http://www.diychatroom.com/att...ve-install-image.jpg

http://www.diychatroom.com/att...e-install-alcove.jpg
Dec 30, 2013, 06:29 PM
Jaybee
Right now, your load is through the end wall of the house, the alcove is just a bump-out. With your vaulted ceiling there is no way to tell if the end gable is framed up to a rafter or top sill, set up as a load-bearing truss or set up as a non-bearing gable end truss that is supported by the studs below.

The short story is that you need to span that full 96" opening with a load-bearing header of some kind. So you need to determine exactly what you have in there. Probably the best bet for accuracy will be to hire someone local with structural experience and/or find a set of plans for your house.

We can speculate all day long from our comfy seats on the internet, but none of us will be able to tell you exactly what you have in that wall.


Jaybee
Dec 30, 2013, 07:03 PM
Mike B83
Ok, thank you. I'm 99.9% sure I have to put a load bearing header in. Just figuring how tall, 6", 8", 10" or 12" and the width also.

I guess I need to talk to a structural engineer or a contractor.

Where would I look for the building plans on my house? Local building department maybe?
Dec 30, 2013, 10:41 PM
Jaybee
Since you are only carrying a gable end roof load and no upper story, a double 2x10 with a 1/2" plywood core will be more than enough header for a 96" span. Make sure that you use double jack studs on either end, not singles.

It is possible that your local building department has plans on file, but not a sure thing. Many code departments do not take plans or only have started doing so recently. Still, it can't hurt to ask. You may also find plans if you can identify the contractor who built the house.


Jaybee
Dec 31, 2013, 12:17 AM
Mike B83
That's what I was thinking too. 2-2x10" with ply in the middle header going across the alcove top where I'm removing the wall.

I will call my county building department tomorrow and I already have an email to the builder so we'll see what happens.

Some people have told me an 2-2x8" header would work too. Do you think this is too small?
Dec 31, 2013, 04:02 AM
Jaybee
A double 2x8 should carry an 8' roof-only span just fine, but here's the thing: You are not in a situation where you are crunched for space. It will take the exact same effort to install a 10" header as it would to install an 8" one. You material cost difference is under $5. Just go with the stronger header.

You can answer all your questions either by removing some exterior siding or removing some interior drywall. With the vaulted style of that room you know that there are either some hefty rafters or flat, engineered trusses going across all the open spaces in the room. It would be 'normal' construction to continue using that same rafter material all the way across to the gable end. If that's the case, then you already have a header in place and no other structural work is needed.

I would approach this as two projects:

#1 - Find out if there is a header in place.
#2 - Install a new header only if needed.

To that end, you could use a stud finder to trace a vertical line above the alcove opening. More accurate - use a nail and tap a series of vertical holes to determine what solid material you have - if any. Most definite would be to cut out a thin, vertical section of drywall and remove for a visual inspection. Even if you decide to cut the drywall, if you find a header in place then all you are in for is a small drywall repair and repaint job.

Installing a new header is a fairly big and invasive project. As you will need to install both king and jack studs, your work area will be 8-1/2' wide and floor to ceiling tall.


Jaybee
Dec 31, 2013, 12:15 PM
Mike B83
Ok, when and if I need to put a header in, don't I put the header under the gable truss bottom chord?

If so I won't need to open the wall all the way to the cathedral ceiling do I?

Am I wrong about how the header would be installed? It will sit on the bottom of the truss chord and hang down the depth of 10" correct?
Dec 31, 2013, 04:00 PM
Jaybee
The header is designed to carry any load that would be over the alcove opening. That load must be transferred from the bottom all the way to the top. If you make the header span just above the opening, then you must still carry load bearing framing (2x's set 16" OC) up to the underside of the gable end framing.

If you have to install a header, there is no way to avoid opening things up from floor to ceiling.


Jaybee
Dec 31, 2013, 08:06 PM
Mike B83
Ok, I got the set of plans from my building department today. Here's an image of the engineered gable truss which sits above the fireplace.

I'm still looking through the plans to see if I can find the wall plans


Dec 31, 2013, 08:35 PM
Jaybee
Your life just got a good bit easier. That's a modified gable-end truss - should be no problem for that truss to span the 8' opening over the alcove area. You should be able to remove the framing that is beside the fireplace and still have enough support without adding in another header.


Jaybee
Dec 31, 2013, 10:43 PM
Mike B83
Thank you for your input and expertise.

That's what the inspector said at the building department too

Thanks again.
Jan 01, 2014, 04:47 PM
Re-mdlr
Aren't trusses wonderful.


They make it look so easy on tv, don't they
Jan 02, 2014, 12:13 AM
Mike B83
I was looking at the floor plans today and they say there are 4x4" beams on each end of the alcove too with Simpson hold downs attached to the foundation. It also said there's a 4x6" just east of the alcove in the wall.

I hopefully will get the wall plans from the building department tomorrow. Sounds like there is a lot of support around the alcove already.
Jan 02, 2014, 01:01 PM
Re-mdlr
Is this a California house, and have you figured how you are going to exhaust pipe the stove with manufacturer and/or code requirements?


They make it look so easy on tv, don't they
Jan 03, 2014, 12:39 AM
Mike B83
No, Northern Nevada. As for the chimney for the stove it's going to be double wall Duratech chimney pipe from the duravent DVL stove pipe up. Going to have to use 2, 45 degree elbows inside the alcove to give me the proper clearance for the chimney pipe. Duravent DVL has 6" clearance to combustible walls, which I will have, 8" to ceilings also which is where it will be. The Duratech chimney requires 2" clearance to combustibles in which I will have a minimum of 3.5" to 5" front and back and 11" on the sides as I am going to frame an 18" X 30" chase around the chimney once it exits the alcove roof.

The stove will sit 7 15/16" away from the rear wall of the alcove in which it needs a minimum 6" so plenty of room there, and I'm going to extend the hearth 14" for a total of 50" which will give me the required 16" of non-combustible material in front and behind the stove. As for the side clearances the stove will have 33" of clearance on each side (which is WAY more than the required minimum of 10").

I'm pretty sure all of my clearance are good to go. As for the chimney height it has to extend 74" above the roofline to meet the 10-3-2 rule. Here's a picture of my plan with the chimney and Chase I drew up.