Structural Question

Wreckers:

Hopefully a quick question that won't require a foray into alt.home.repair . . it's downright scary over there.

I've what I believe to be a bearing wall with a 30" doorway.

The wall is around 12' long.

I'd like to open the doorway into an arch around 10' wide.

How deep does the joist need to be? This is a ranch with the attic directly above, in snow country (NW NJ).

I'm assuming a sistered Tuba-Ate or Tuba-Ten?

Thanx

Charles

Reply to
U-CDK_CHARLES\Charles
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I am an inveterate DYI'er myself, but in a situation like this you will most probably do yourself, and/or your heirs and future assigns, a big favor if you have an engineer to take a look at it and design the opening properly.

I routinely pay an engineering firm around 2K to design the framing and foundation for an entire 2 story house, so the cost should be reasonable for that small of a job, and worth the piece of mind and future saleability/liability.

Reply to
Swingman

Always consult a structural engineer -

The two-bit answer. The general rule is 1" of 4" x for each foot of opening. 10' opening, 4" x 10"

Dave

Reply to
TeamCasa

The "Rule of Thumb" is 1" of depth per foot spanned, so a 4x10 or 2 2x10 with 1/2" ply spacer would be the minimum. Here's a link with a little more info:

-Doug

Reply to
Doug Winterburn

Ranch house and internal bearing wall seem somewhat conflicting. Personally I'd be thinking LVL but let an architect tell you.

Reply to
Eric Johnson

Ditto the others.

1 nominal inch per foot of span. Build a header as a ring for 2x6 construction.

Example: for a 7' span use 2x8's (round up to the next size if lumber) and connect them top and bottom with a ripped 2"x1.5" strip top an bottom to make the sandwich the full 5.5" thickness of the 2x6 wall.

Architects are overrated. I hired one to help out with a roof truss design and they came back with a design that *I* proved to be over-engineered. The point of the consultation was to make sure that I had a safe design without going to undue expense.... they gave me an overwrought design that required considerably more material and labor to implement.

Reply to
Stephen M

If you do not know for certain if it is a bearing wall it is impossible to tell. First step is to determine the load and then size the beam for the load.

2 x 2x8 seems unlikely in any case. Note that different species of wood have greatly different strengths. Personally I'm fond of LVL. Always straight and free from knots and you can get by with a smaller beam.

-j

Reply to
J
J

I'm not engineer and I've only built one house, but can't you determine if it's a bearing wall by what's directly underneath it? You need support directly in the basement under that wall, you can determine by the way the joists are running.

Glenn

Reply to
HopsNBarley

Could it be that you asked the wrong profession to do the job and they overdid it out of ignorance? The LAST thing on earth I would do is hire an architect to engineer a structural solution ... most wouldn't take the work, IME

Reply to
Swingman

It's a bit complicated.

Most of the house has a full basement. However the full basement stops "more or less" beneath the kitchen where the excavator encountered more rock than they cared to deal with.

Beneath the kitchen there's a crawl space, the basement ending in a wall made of 8" block.

The framing in the basement is parallel to the wall in question. The wall itself is clearly just a 2x4 wall.

The floor joints are 2x10s on 12" centers, supported directly below the roof peak (there's a row of columns in the basement directly beneath the peak).

There is electrical and telephone in that wall. It should be evident whether the wall coincides with the end of the full-basement from below.

If they are not cooincident, then the wall is NOT load bearing?

Though I suppose very little would be lost in using sistered 2x10s in that application.

Reply to
U-CDK_CHARLES\Charles

Correct. It was an enginnering question. I believe this was an artchitectural and engineering firm.

It's a small community in which there is little distiction. My request was clearly inside the scope of their ability If it was outside the scope of what they want to do they could have said "no thanks".

I bare the responsibility for not making it absolutely clear that their job was find the *least costly* solution rather than just a functional one.

Reply to
Stephen M

If this is a truss roof, all the trusses are the same and they don't all "catch" the wall in question it is unlikely the wall is holding up anything. Usually trusses only hang on the outside walls unless you have a complex roof line or the wall goes the whole length of the house, perpendicular and somewhat centered on the trusses. If this is one of those designs with a lot of breaks in the roof line you really need an engineer or a copy of the truss engineering.

Reply to
Greg

Since you have to tear the sheet rock out any way go with 2, 2 x 12's with a

1/2 piece of plywood between the two.
Reply to
Leon

Not necessarily. Sometimes that can give you a clue, However, you can tell if it is a bearing wall by what is directly ABOVE it. This is also complicated by the need for some walls to resist lateral (sideways) loading which is needed in areas with seismic and/or wind conditions.

-j

Reply to
J

lots of folks seem to know the construction end of it.. I'd suggest you check with a local contractor (NOT THE CITY!) about building codes and "common practices" in your area before you start..

Sorry, with a wife in law school and my real estate experience, I always look at potential liability first..

Not being "up to code" is worse in most places than not getting a permit to do the work.. also makes it a little sticky legally if you sell the house..

Reply to
mac davis

You better believe it. The kiss of death to a builder is the phrase "not built to industry standard" ... it can be as small as a 1/2" drop on the corner of a brand new garage foundation that is perfect in every other way, and it can influence the sale of the entire property, or worse, lead to legal liability long after the fact.

In this day and age you can't be too careful with _anything_ you do to a house that you're not planning on dying in.

Reply to
Swingman

My experience is only in Calif., but if you get caught with work done without a permit, (usually during a sale), the first thing they do is have a building inspector come out... If the work is up to whatever the code was when it was done, they sometimes will let you slide and just fine you and sell you a permit.. If it isn't up to code, they make you tear it out and get a permit to do it right... not a lot of fun when the buyer wants to close the sale and you have an offer out on another house..

Reply to
mac davis

Who does the checking? I've live in PA and CT and owned a few houses so I'm not an expert, but none have ever been inspected for permits or work done over time.

When I lived in Philly, sometimes a nasty neighbor would turn in someone. If the inspector came out, you could "buy" a permit on the spot with cash. Otherwise, they never bothered a homeowner. Ed

Reply to
Edwin Pawlowski

Around here folks are paying third party house inspectors, many of whom have credentials from either the structural engineering side, or as long time city inspectors, now freelancing, to do the checking. It's grown to a pretty good size cottage industry. These folks often use a trail of building plans, survey's, permits, etc. that are most often a matter of public record at many local government offices these days. Doesn't take much digging to find issues that may be a future liability to someone who didn't cross the t's or dot the i's.

All in all, it's not a bad thing ... thank your local government bureaucrats and computers for the data, and your tax dollars for the implementation.

Reply to
Swingman

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