Tall Anchor Bolts

**Gunnar Alquist** · 05-06-2015, 10:16 PM

The anchor bolts under a 2005 single-story home I inspected today were elevated higher than normal. Generally, anchor bolts are mounted to the forms to ensure correct placement and depth, but I don't know if it was common 10 years ago. In addition, bolts vary in length, so even if they stick up higher than normal, they might have the required depth. There were a lot of bolts and threaded hold-downs. I assume that the bolting requirements were noted in the plans or specifications, but the plans were not available.

So the question: Is this a reportable condition? There are a lot of unknowns here, and I cannot say for sure there is a problem. Further review would probably require a pachometer and maybe even coring the foundation to determine depth. An expensive endeavor to find out everything is fine (if indeed it is).

Thanks for your time.

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**Dom D'Agostino** · 05-07-2015, 05:21 AM

Embedment is the critical part, according to IRC R403.1.6, you need a minimum of 7 inches into concrete or grouted cells. So you would need to know the length of the bolt in order to be concerned:

R403.1.6 Foundation anchorage. Sill plates and walls supported directly on continuous foundations shall be anchored to the foundation in accordance with this section.

Wood sole plates at all exterior walls on monolithic slabs, wood sole plates of braced wall panels at building interiors on monolithic slabs and all wood sill plates shall be anchored to the foundation with anchor bolts spaced a maximum of 6 feet (1829 mm) on center. Bolts shall be at least 1/2 inch (12.7 mm) in diameter and shall extend a minimum of 7 inches (178 mm) into concrete or grouted cells of concrete masonry units. A nut and washer shall be tightened on each anchor bolt. There shall be a minimum of two bolts per plate section with one bolt located not more than 12 inches (305 mm) or less than seven bolt diameters from each end of the plate section. Interior bearing wall sole plates on monolithic slab foundation that are not part of a braced wall panel shall be positively anchored with approved fasteners. Sill plates and sole plates shall be protected against decay and termites where required by Sections R317 and R318. Cold-formed steel framing systems shall be fastened to wood sill plates or anchored directly to the foundation as required in Section R505.3.1 or R603.3.1.

Dom.

**Jim Luttrall** · 05-07-2015, 08:20 AM

Originally Posted by Gunnar Alquist

The anchor bolts under a 2005 single-story home I inspected today were elevated higher than normal. Generally, anchor bolts are mounted to the forms to ensure correct placement and depth, but I don't know if it was common 10 years ago. In addition, bolts vary in length, so even if they stick up higher than normal, they might have the required depth. There were a lot of bolts and threaded hold-downs. I assume that the bolting requirements were noted in the plans or specifications, but the plans were not available.

So the question: Is this a reportable condition? There are a lot of unknowns here, and I cannot say for sure there is a problem. Further review would probably require a pachometer and maybe even coring the foundation to determine depth. An expensive endeavor to find out everything is fine (if indeed it is).

Thanks for your time.

On new construction I would be a bit more critical but in reality, we never know the depth of embedment. They might have used longer bolts in order to allow for a double bottom plate... but more than likely they are too shallow. I doubt I would mention it on an existing home, but that is just me.
Probably cheaper just to add a bolt than to core if it is just a few bolts rather than the whole house.

**Jerry Peck** · 05-07-2015, 01:34 PM

... ummm ... What was the question? I was busy reading the 'This Side Down' and 'Strength Axis This Direction' label on the OSB ...

**Gunnar Alquist** · 05-07-2015, 05:46 PM

Originally Posted by Jerry Peck

... ummm ... What was the question? I was busy reading the 'This Side Down' and 'Strength Axis This Direction' label on the OSB ...

Crap.

**Jerry Peck** · 05-07-2015, 07:00 PM

Originally Posted by Jerry Peck

... ummm ... What was the question? I was busy reading the 'This Side Down' and 'Strength Axis This Direction' label on the OSB ...

Originally Posted by Gunnar Alquist

Crap.

Not to worry ... that strength axis may only apply to roofs and floors (as would the 'This Side Down' label) - wall sheathing can sometimes be installed long dimension (strength axis) parallel with the studs, depending on thickness it may need the ends joints blocked.

Roofs and floors are much more critical for being installed perpendicular to the supports. Also, for roofs and floors, the minimum size piece allowed is: 24" minimum width and long enough to go over two spans and three supports.

For walls, I haven't found a minimum size - so I leave to to "full sheets" and let the engineer sign and seal what is less.

**John Kogel** · 05-09-2015, 08:38 PM

Hey Gunnar, if those bolts were bent over with a sledge hammer, would you say anything?

Seems to me some builders did that here in the mid-century, bent over minus the nut and washer.

**Gunnar Alquist** · 05-11-2015, 10:30 PM

Originally Posted by John Kogel

Hey Gunnar, if those bolts were bent over with a sledge hammer, would you say anything?

John,

Not sure how that relates. Bending over bolts would be readily visible, and there would be no question that it is wrong. However, depth of an anchor bolt cannot be determined visually because bolts of varying length are available. The amount of exposed threads is not necessarily wrong, but it might be an indication. That was the primary reason for my question.