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I live in a brick house, and am interested in understanding whether it is brick or brick veneer, as a way to understand what kind of risks it (and we) may face during an earthquake.

I hear that brick veneer is essentially a wood frame house with a brick facade and fares better in earthquakes than a pure brick home.

Our house is in the Pacific Northwest of USA, was built in the early 1930s, and is a 1½ story home. Any advice on how I would know one way or the other?

The foundation is bracketed to the wood framing that sits on top of. I assume this means it's a veneer, but would love to confirm.

Brick house

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One way is by looking at the bond of the bricks. Your bricks are arranged in a running bond or stretcher bond, which is always one brick thick:

enter image description here

To be a structural brick wall it would have to be more than one brick thick, or have multiple wythes, and you would see headers, like this:

enter image description here

It's likely your walls are wood-framed with single-wythe brick veneer on the outside. But to really know what was on the inside, you would have to see inside them. The easiest way is to remove some outlet covers and look behind the electrical box. If you see an open void, it's a wood-framed wall. If the area around the box is completely solid, you might have concrete blocks making up the structure of the wall.

Beautiful house, by the way.

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    You would not necessarily see headers like that. I have seen load bearing walls made of an inner and an outer wall each only one brick thick. Since the inner and outer walls were separated by insulation, they could not be connected by bricks like in your image. – kasperd Jul 16 '15 at 8:22
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    What @kasperd said. In the UK, cavity wall construction is very common, whereby you have two skins of bricks, connected by wall ties. Both skins have only stretcher bonds. – AndyT Jul 16 '15 at 9:15
  • Good point. I didn't realize that single-wythe brick walls were used structurally in the UK! – iLikeDirt Jul 16 '15 at 14:19
  • According to Wikipedia "A cavity wall with masonry as both inner and outer skins is more commonly referred to as a double wythe masonry wall." I'm not sure about the "more common" bit, as I've never heard of a wythe in my life, but hey. – AndyT Jul 16 '15 at 16:11
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    Either way, the outer wythe of brick is not structural unless there are exposed headers. To know what material the inner structural wall is made out of, you'd really need to be able to see it for yourself, hence my suggestion to look behind receptacle covers. Here in the USA, structural single-wythe solid brick is uncommon; usually the structural wall would be a wood frame, concrete blocks, or, more rarely, hollow clay bricks. – iLikeDirt Jul 16 '15 at 16:53
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The frame is of wood. The brick is a cladding on the outside. It is not a veneer. A veneer is fake layer of thin brick-like parquets that are secured with a cement or glue to a backing of some kind. In other words a stone or brick veneer does not have full-sized bricks. Your house does have full-size bricks, but they are not used for structural purposes. It is just a layer or cladding on the outside used as decorative brick and weatherproof surface.

Brick is rarely used for structure in small buildings made in the last 150 years unless they are very small (one room structures). If your house used brick as the structure, it would be obvious because you would have thick 16" to 24" square brick pillars or columns going up through the center of the house upwards from the foundation and the walls would be solid brick. Like you drill through the plaster to hang a picture and there is brick there. Brick buildings do not require interior walls so they were mostly used for factories and warehouses where big open space is useful.

In a brick house there is no framing or sill. There are just big cross beams that sit tenoned right in the brick and the joists hang across them. The walls are all solid brick.

It is hard to know how well a given house will withstand an earth-quake, unless you are a structural engineer. In earthquakes sometimes one house will fall down and another next door stays up. Both quality of construction and design have a factor.

The type of house you have is called a "stockbroker Tudor."

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    Don't necessarily count on brick not being used for structure, it depends on where you are. I grew up in a small town that was once home to a brick factory. Many of the houses there are less than 150 years old, but the walls are definitely made of solid brick. When practically everybody in town is either a brick maker or a brick layer it's cheaper to build them that way, and probably faster since good carpenters would be where your labor shortage lies. – Perkins Jul 15 '15 at 20:06
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    Well, the answer has some good points. But the paragraph saying "brick is not used for structures under 150 years old" is just plain wrong. I'll concede that a brick structure is not common in the US, but it is still used, and in the UK is used extensively. – AndyT Jul 16 '15 at 10:07
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    @AndyT i have never seen a modern brick and beam house. Document one. – Tyler Durden Jul 16 '15 at 13:32
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    -1 There's a lot of misinformation and assumptions in this answer, and it only helps the OP. It doesn't help future visitors determine if their house is structural brick or just cladded. – Darrick Herwehe Jul 16 '15 at 13:34
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    @DarrickHerwehe I would take exception to that. I specifically pointed out several key determinants which other people with the same question can have, namely that brick houses have no sill and they have solid brick columns and solid brick walls. – Tyler Durden Jul 16 '15 at 13:37
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Open a window and measure from the face of the brick to the inside wall. If it's 14 plus inches, that's at least two courses of brick. It will be obvious if it is; questionable if it's any less thick than that.

One brick (4") and a 2x4 stud wall = ~8"

Two bricks and a stud = ~12"

Add 1" if it's lath and plaster; add 1/2" for drywall. Allow another 1/2" for 'play'.

You'd need to know if it's furring strips or a stud wall (one-by, 2x4's or 2x6's?). 1930's construction, I'd have to assume furring strips, but do as Dirt suggests and look behind an outlet.

A measurement of ~10" could either be a single course with 2x6's, two courses with furring or just a giant gap. You need to find the distance from the face of the wall, to the inner brick and subtract that from your original measurement. Round to the nearest multiple of four, divide by four and there it is.

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Go to the inside face of an external wall and knock on it. If it sounds hollow, then you (probably) have plasterboard over a timber frame, meaning the external bricks are cladding only. If it sounds solid, then you (probably) have a structural brick cavity wall.

This method isn't foolproof (for example you might have a structural brick wall where somebody has put up battens before fixing plasterboard), but it's a good indication.

  • Not sure why nobody seems to like this answer - it's exactly how I discovered my house was timber framed! – AndyT Jul 17 '15 at 13:07
  • Because sometimes what it feels or sounds like means nothing. – Mazura Jul 20 '15 at 23:31
  • @Mazura - thanks, and an interesting situation in your link - I've never heard of that sort of construction. – AndyT Jul 21 '15 at 8:12
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As the answers so far have shown, there are so many combinations of frame and masonry construction that most external signs can be deceptive in one way or another. In fact, with a little ingenuity, one could disguise almost any type of construction as something else. My house is brick & block, but it's dry-lined, so the the exterior walls seem hollow on the inside and the lintels are the same angle-iron one would find on an anchored-brick-veneer wood-framed structure. Even the condo-docs are written up on the assumption that the buildings are wood-framed, since residential block construction is rare in the N.E. U.S.A. . There are even developments nearby with the same floor plans that were built wood-framed, with aluminum siding. My favorite method of determining if a structure is wood-framed would be to look between the floor joists in the basement or crawl space where they go into an exterior wall; if you see a rim joist, it's almost certainly wood-framed from that point, upward. If you see bricks or blocks separating the joists, the walls above are probably structural masonry, though they may well change to wood-framing further up; it's very common to have a ground story in masonry and a wood-framed story above that. The more work you do to the house, the more of its inner secrets will be revealed.

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