Metal straps instead of anchor bolts on slab foundation

I am looking for information on anchoring the wallplate to the foundation. The builder used metal straps embedded in the foundation, wrapped across the top of the plate and secured, instead of anchor bolts. Interior walls secured with the ‘shot-in’ type anchors.

Anyone seen this type of strap application?
Does it hold as well as anchor bolts?

Any information appreciated.




It would depend on what’s required for your area according to it’s seismic classification and the soil category - i.e. D2 seismic SM soil…

Here they generally use 1/2 inch anchor bolts (“j” bottoms) 10" deep and within 6" of the corners - strung every 14" or so On Center.

Covers even the worst applications here. I’ve seen sill plates strapped on detached garages here but not on a home…

Sorry for the expanded answer… it depends :smiley:

I’ve seen those straps on a tv show, sorry give me a sec, they were explained to be used in high wind areas.



Looks like a Simpson Mudsill Anchor…D47

I don’t see any problem in your picture anyway.

Looks like IRC Building Code approved and Simpson manufactured MASB mudsill anchor ties:

See here for more:

(Roll your cursor over MASB in the link for details)

Or it may be a USP FA3 or similar foundation anchor:

See 2006 IRC R403.1.6 for foundation anchorage details.

Such are Code-approved engineered wood-to-concrete or wood-to-masonry sill plate to foundation anchors when installed according to the manufacturer’s installation instructions.

These are very commonly used and often more commonly used than traditional anchor bolts.

Without you telling us from field observation:

  • the manufacturer of the engineered product
    -the manufacturer’s part number
    -and the manufacturer’s installation instructions…

… nothing can be further said about whether these anchors have been properly fastened, installed, or anything else.

IRC now requires wall straps in specific areas of wall panels.
It has to do with wind resistance.
My code book is in my truck so I can’t site specifics and I’m too lazy to go get it.
The point would be this is O.K. and you will see more of it in new homes.
IRC also gives alternate methods of building braced wall panels when straps aren’t used.These methods have to do with specifics of wall panel placement and specific nailing patterns.

We use straps in MI all the time. I’ve never seen one used on a slab, though. Every city I ever did contractor work in required we use Red Heads or similiar anchors (wedge or sleeve). The straps would have made our job a lot easier.

I know the straps are approved, but I do not think they are the equal of properly-installed and properly washered anchor bolts, and I do not like them. Some srtaps are designed to be used **in addition **to anchor bolts, not instead of them, and those are often mis-used as anchors alone. If straps are used, every effort should be made to ensure that the straps are exactly the ones that are code-approved for use in place of anchor bolts, and that their installation and fastening conform to their manufacturer’s written instructions.

The only time I see straps like talked about here is for the installation of Modular Homes Installation, other than that, it is the regular 1/2" x 8" anchor bolt like it should be.

People are getting lazy and taking shortcuts and all relates to the fast green backs. If you know what I mean.

Marcel :slight_smile:

Here’s a little more info from what I know. I’m sure the websites provided from others may have already well explained to you your question. they are indeed, obviously called anchor straps. These require a much deeper embedment in the concrete versus the anchor bolt. Not less than 15" is what I’ve found. The spacing too is limited to a smaller O.C. of 4 ft. rather than 6’ for the bolts. They should also have been installed as a “Y”. Meaning the strap should wrap the sill plate from each side. However, in my opinion a much better way to use this anchor strap would be to drill a hole (in consideration on the anchor strap width) and run the entire strap through the hole as the plate is applied then spread the strap outward wrapping both sides of the plate. Also I have read that these straps cannot be ran up the side of a stud, require a min. of 6 - 8d nails and when wrap they must overlap, not to be at a diagonal. Hope this has helped you.
Oh yeah, as for the interior walls being “shot down” that is fine, only exterior walls require anchoring to the degree of bolts or straps.