Half cathedral ceiling, half trusses?

[54FordPanel]

Hello. I am new here, and I've been up all night surfing the web, trying to find some answers. Before we put in a bid on a house that we are interested in buying, I need to know if I can remove some interior walls. This house is a tri-level, and the main level with the living room, dining room and kitchen is 22' deep and 18' wide. If you took a square and made 4 quadrants out of it, the kitchen is in the upper right quadrant. It has a flat ceiling, and looking up into the attic above the kitchen area, it has 2X4 "truss" type construction over that area. I'm thinking it was done that way to give something to attach the dropped ceiling and walls to?
The rest of the main floor, in a L shape, has a cathedral ceiling. I can't see a exposed "beam", but there is a phony beam running across the ceiling at the peak. I don't think it's hiding a structural beam, but I don't know for sure. I'm new to that kind of construction, as all my houses in the past had trussed roofs.

My question is this: If the roof is built cathedral style, could that wall making the back of the kitchen, directly under the peak of the roof, be a bearing wall? Or would that be mixing 2 different types of roof, and not very likely? Or if I took out that wall would I need to put in a structural beam, spanning the width of the house, to support the roof? Are there 2 different types of ridge beams: one as a bearing beam vs one as a ridge only?

I have no problem hiring a engineer to look at this before I tear into it, but I need to know what I'm looking at before I get too interested in this house.
Any help you can give me is greatly appreciated. I'm not stupid, just ignorant on this....and maybe a few other things.....

[mjpliv]

Based on your description it is entirely possible that there is a structural beam under the "decorative" one. There are three ways to build the catherdral ceiling/roof I think you are telling us about.

1. It can be built with engineered roof trusses. In this case the section through the roof would be fairly thick (2-3 feet) and probably have different slopes inside and out (say 12/12 on the outside slope and 10/12) on the inside slope. It is possible to manufacture these trusses to clearspan the building with minimal lateral deflection (outpush).

2. It could be built with a RIDGE BEAM and rafters. This type of assembly creates roof loads that go straight down and do not require any wall restraint for lateral loads (outpush)

3. The roof could be built using a RIDGE BOARD and rafters but this type of construction would require some sort of lateral restraint for the walls due to the large loads created by the rafters pushing outward against the walls as the roof trys to deflect. This restraint would be in the form of wooden collar ties or metal rod used to tie the tops of the walls together. If there is no restraint visible your house was probably built with option 1 or 2.

[mjpliv]

And to answer your specific question, it is a good possibility that the wall in question is load bearing or at least portions of it.

[54FordPanel]

And to answer your specific question, it is a good possibility that the wall in question is load bearing or at least portions of it.


You could very well be correct. I think I can discount engineered roof trusses. So; if I don't see collar ties* (*term is the result of web surfing, and may be incorrect), then that means the roof must necessarily have a load bearing beam to hold it up? I thought I saw someplace that some cathedral ceiling are engineered with ridge boards (not beams) that work without collar ties? No?
And if they went to the trouble of building cathedral ceilings, why would they need a bearing wall for 1/2 of it? Wouldn't they have just made the bearing beam span the whole roof?

[mjpliv]

The reason would be to provide a bearing point at mid span. A beam spanning the full 22 feet carrying a roof 18 feet wide would generate a column load in the area of 7100 pounds at each end (25% of the roof area times the factored snow, rain and dead loads) and the beam would have to be deep enough to provide minimal deflection values supporting about 700 pound per linial foot of beam.

[54FordPanel]

Thanks for taking the time and answering, I appreciate it.

[mjpliv]

No problem! Please drop back and fill us in on what you actually find if you open up some walls. Remember, I am just guessing.

[54FordPanel]

I'll probably pass on the house. It's a great deal in a great neighborhood, but the kitchen is just too small. The house we are in now I tore out 2 walls and built a dream kitchen. In this house I was considering, apparently, I would have to bring in a 22' beam, hang it 14' in the air, yada, yada, yada. Or hire somebody to do it.
Nuts : (
If I were to hire somebody to look at it, could they tell the true status just by looking in the attic on the flat ceiling kitchen part? The house inspectors I have dealt with in the past wouldn't have a clue....would I look for a "structural engineer" in the phone book, or just who exactly?

[mjpliv]

Look for "consulting engineers" or "structural engineers"

[54FordPanel]

Ok, thanks. And they would be able to tell just by looking at it?

[mjpliv]

Any structural engineer or architect would be able to do that for you