Identifying a Load Bearing Wall

[crokett]

A friend asked me about identifying a load bearing wall. He wants to take one down and wanted to know if it was load bearing. He does not know if his roof framing is joist/rafter or trusses. He does know the wall runs perpendicular to the framing. The layout of the building is it is approx 15x25. Along the 15' dimension there is a wall that runs parallel to the roof framing that divides it in to 2 spaces approx 15x14. and 15x11. There is a wall that then runs perpendicular to the roof framing that divides the smaller space into 2 spaces. It is this wall he wants to remove.

Assuming it is trusses, then by definition the wall is not load-bearing correct? Also, since the wall does not run all the way across the building then it probably is not load bearing, correct? Is there a way to tell by climbing into the attic and looking at it?

[Uncle Cracker]

If the span of the trusses is only 15 feet, it is doubtful that there would be a load wall other than those on the perimeter, but there are exceptions. Best way to find out is to remove it. If the roof falls in, it was a load wall...

Most load walls will be double-plated at the top, and possibly double-studded at intervals. If he can get a look, either from the attic or behind the drywall, any such reinforcement might be cause for concern... Also, if there is crawl space or basement, looking at the framing and support under the wall could be revealing, or if it's on a slab, drilling the slab near the wall could disclose a thickening of the slab or a footer if the wall is a load wall.

[Mr__Bill]

If the span of the trusses is only 15 feet, it is doubtful that there would be a load wall other than those on the perimeter, but there are exceptions. Best way to find out is to remove it. If the roof falls in, it was a load wall...

Yeah, what Uncle said. I know a few people who tried this and it really works. In this setup you may see the long walls start to bough out first.

[JimD]

Since the wall is perpindicular to the trusses, it is helping to support them. The question is if it needs to.

Are the trusses in the area of the wall any different from the trusses that presumably span the entire 15 feet? If not, then the wall in not necessary. If they are, then you need to add support prior to removing the wall.

Jim

[LarryG]

If the roof spans the entire 15' width in the 15x14 space, it would be reasonable to assume it spans the entire width in the 15x11 space, too, meaning the wall that subdivides the smaller space into two rooms could be removed. The kicker is that a building this small might not have a truss roof ... a building only 15' wide would more often than not have a stick-framed roof.

Technically, the presence of trusses does not necessarily mean the walls are non-bearing, although for a span as short as this, they probably aren't. Also, the number of plates at the top doesn't really tell you anything as all walls, bearing or not, are typically double-plated at the top.

Bottom line is, the only way to be sure is to get up in the attic and look. If the ceiling joists overlap above the wall in question, it's load-bearing.

[jking]

Uncle & JimD are both spot on. If the wall in question appears to be reinforced or has support underneath it, it is likely a load bearing wall. Two different truss styles from one area to the other would also indicate a likelyhood of load bearing.

If access is gained to the rafter/trusses & they end up being trusses, look at the pattern of the diagonal members. If there are no members intersecting above the bottom chord above the wall (and especially if there is no vertical member), this would indicate the truss is probably designed to span the entire width.

If I understand correctly, the roof members would span the 15' direction. If this is a gable roof, it would not be unusual for this to be raftered to span the entire 15' direction.

[Uncle Cracker]

Since the wall is perpindicular to the trusses, it is helping to support them.

Not really... Interior walls that are not load-bearing are typically not even built until the trusses are in place and roofing is "dried in". If there is any connection to the trusses at all (they may spike a nail here and there to keep the top of the wall in place), it's strictly cosmetic.

[messmaker]

When you remove the wall, wear a hard hat. If that ends up being a good idea, it was a load bearing wall.

[cabinetman]

Not really... Interior walls that are not load-bearing are typically not even built until the trusses are in place and roofing is "dried in". If there is any connection to the trusses at all (they may spike a nail here and there to keep the top of the wall in place), it's strictly cosmetic.

QFT. That's hittin' the nail on the head.
.

[crokett]

Ok. I will get up in the attic and take a look around. Assuming the construction is joist/rafter and not trusses I will also measure the actual span and check the span tables.

thanks fellas.

[Alex Franke]

Best way to find out is to remove it. If the roof falls in, it was a load wall...

:lol: Thanks for the laugh!!

[pelligrini]

I would seriously doubt that the wall dividing the 11x15 space is a load bearing wall, especially if it were truss construction. If someone went to the effort of doing trusses for such a small structure I would bet that they wouldn't engineer and construct two different types of trusses. It is highly unlikely, but certainly not impossible.

[ragswl4]

If in doubt, support the ceiling before removing the wall. It wouldn't be too difficult to add a support beam if the wall was load bearing. Check a span table for the right size header. But do it before the wall comes down.

[Tom Slick]

Does the house have a crawl space? if it does you can look for piers/supports under the wall in question. If it is load bearing it will have some type of support.

[jonmulzer]

Not really... Interior walls that are not load-bearing are typically not even built until the trusses are in place and roofing is "dried in". If there is any connection to the trusses at all (they may spike a nail here and there to keep the top of the wall in place), it's strictly cosmetic.

Perhaps where you live that is true, but here it is not. All walls are double-plated at the top. It is done to get the overlap at any butt joints in the top plate and make the wall a lot more rigid. Back in the day I framed a ton of houses and all of them were done this way. I still work around residential construction and see they are even done this way on prefab tract homes. I find regional differences fascinating though and you are correct that it is not really necessary. It does make for a better home though if all top plates are doubled up.