Increasing size of existing header

Posted by on February 7, 2009, 12:35 pm

I have a 8' span of 2x8 dbl header with post in middle. I want to
remove post which requires increasing header depth. Is it allowable to
increase header depth by adding an additional 2x4 dbl header
underneath existing to meet code. (this would be done with temp
supports in place of course)
Thanks in advance
g

Posted by dpb on February 7, 2009, 12:58 pm

geojunk@hotmail.com wrote:

> I have a 8' span of 2x8 dbl header with post in middle. I want to
> remove post which requires increasing header depth. Is it allowable to
> increase header depth by adding an additional 2x4 dbl header
> underneath existing to meet code. (this would be done with temp
> supports in place of course)

Unless the added is somehow joined with the existing along it's length
so they act in concert the additional 2x4 will do virtually nothing.

Problem w/ doing the above is probably don't have the extra wall
thickness to give up to add the necessary gusseting on both sides.

I'd say need to replace the existing 2x8 w/ a 2x12 if that's what's
indicated.

Alternatively, it's likely although I didn't do calc's, that one could
take the half-inch filler would presume is between the existing 2x8's
out and replace w/ 1/2" plate bolted through and get sufficient
additional load capacity w/o actually dropping the opening.

This probably also means temporary jacking to remove the existing as
well as does the full replacement option.

At least, I'd suggest getting an engineer's input if considering
anything like the original suggestion--again I didn't do the calc's but
I don't think a single 1/2" ply would be sufficient gusset to do it and
to get it in would require pulling the header anyway so what's to gain?

--

Posted by on February 9, 2009, 11:34 am

On Feb 7, 12:35=A0pm, geoj...@hotmail.com wrote:

Code will never allow it but if you epoxy the 2x4's to the 2x8's the
entire length you will get the strength you need. Needs to be good
quality epoxy applied liberally. Clamp or jack the 2x4s tightly
against the existing and leave it to harden minimum 24 hours. I
suggest www.uscomposites.com

Posted by Roarmeister on February 9, 2009, 8:00 pm

On Sat, 7 Feb 2009 09:35:50 -0800 (PST), geojunk@hotmail.com wrote:

>I have a 8' span of 2x8 dbl header with post in middle. I want to
>remove post which requires increasing header depth. Is it allowable to
>increase header depth by adding an additional 2x4 dbl header
>underneath existing to meet code. (this would be done with temp
>supports in place of course)
>Thanks in advance

You didn't state whether you have a 2x4 or 2x6 stud wall thickness
which would have helped. In a 2x4 wall, you usually have a doubled
header which gives you 3" depth, whether the contractor added another
1/2" piece of plywood and sandwiched it with the 2x8's you didn't
mention OR is their simply and air gap and insulation?

If you are pinched for space and don't want to change out the header
to something deeper like a doubled 2x12, you could remove the original
2x8 header and create a fletch header of steel plate and wood members
- refer to an engineer for the design. You could also check out the
possibility of using an engineered wood header instead.

Simply adding a secondary header under the primary header would not be
sufficient as they likely would not operate together as a single unit
- even if you could it would probably need to be engineered.

If you have a 2x6 wall then you could change it to a tripled 2x8
header or a fletch header. You have more options available to you.

BTW, I am assuming you have a complete span header in place right now
instead of 2 smaller spans. If you have two smaller spans then the
middle post probably had jack studs on it as well for the header to
rest on and the procedure for replacing the header is just a bit
different than for a longer simple span.

Posted by bmancanfly on February 22, 2009, 9:30 am

bmancanfly had written this in response to
http://www.thestuccocompany.com/construction/Increasing-size-of-existing-header-16454-.htm
:

-------------------------------------
geojunk@hotmail.com wrote:

Why are you certain that you need to increase the size of the header? If
it is a continuous 4" X 8" X 8' header, depending on what's above it, you
"may" not need to.

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