Can I anchor a mudsill to a 100-year-old house foundation using wedge bolts 58 x 6 in, going 4in deep, or should I use all thread bolts with epoxy instead?
Asked by Theo Boyer 
3 months ago
Last Updated: September 1, 2024
Hey, I’m looking for some advice on how to anchor a mudsill to a foundation for my 100-year-old house. The foundation doesn’t have any rebar, and the mudsill isn’t bolted down. Do you think using wedge bolts, specifically 5/8 x 6 inches, would work? The mudsill is 2 inches thick, so that would leave 4 inches into the foundation – is that deep enough? I was thinking of adding some epoxy as well. Or do you think I should use an all-thread bolt and epoxy for extra security? Thanks in advance for your advice!
For anchoring the mudsill, wedge anchors are not the best choice. If space allows, I’d go with a Simpson Titen HD screw anchor as my top pick. Alternatively, threaded rod with epoxy could work. Make sure to use a 2″ x 2″ square washer with either option. If drilling is a challenge, Simpson may offer retrofit anchoring plates.
Are you thinking of using the 3-inch square plates instead? Have you considered using anchor wedges?
Hey , is this a code violation?
I haven’t been in the thick of things like this for work in a while, but as far as I remember, they weren’t considered seismically safe due to the small anchor point of contact (the bell end of the wedge). This means that it requires less force to cause damage to the small area and ultimately cause the anchor to fail.
I see. That’s why I was thinking of using the xp22 epoxy with them.
It looks like a HD screw might be more reliable
I’m not sure if it is. I haven’t been in the industry for 13 years but I wouldn’t trust them for my home.
The Titen HD has some pretty impressive mechanical testing ratings, according to an anonymous participant.
Hey there! If you’re thinking about using epoxy, threaded rods would actually be a more cost-effective option. Plus, they provide more surface area for the epoxy to grip onto, especially when dealing with vertical pressure.
It might be a code violation, depending on your location. What kind of foundation does the house currently have if it’s 100 years old? Is it made of rock, like granite boulders? In the northeast, old houses often have granite boulder foundations, which should guide your decision. It’s a good idea to meet with the building inspector for more specific information about your area.
Just swing by your local Hilti and inquire. If the code in your area doesn’t permit something, then others won’t buy it locally either, so they probably won’t have it in stock where you are. And hey, if you purchase enough epoxy, they might throw in a free battery epoxy gun. :p
Yup, is right. Hilti will for sure be familiar with the local code. Just make sure to chat with someone who’s been there a while.
They say is seismic rated on the box.
They used epoxy and large threaded rods over an inch in diameter to secure heavy equipment at the power plant we were constructing. Instead of the usual short shields we used to hang things from the ceiling, we drilled those threaded rods several inches, about 5-7 inches, into the concrete. We made sure to vacuum and brush out the holes to prevent any stray dust from preventing the epoxy from bonding properly to the concrete. We learned from past experiences on other job sites that if the anchor holes were not drilled to the correct depth, or if the person using the rotary hammer wasn’t steady and created a hole that was too big, the mechanical anchors could come loose. For non-structural base plates for metal siding, the anchors in the video might not be long enough to secure two 2x materials. In that case, rods could be cast a foot or deeper into the concrete and tied to rebar. An engineer might also need to approve the materials used, as rainwater could cause corrosion over
Can you tell me what seismic load they are rated for? Do you think it will be strong enough for the load on your foundation?
If the house has stood for 100 years without being bolted down, I wouldn’t stress about fixing something that isn’t broken. Just do what’s necessary. Unless an inspector requires something specific, keep things as they are or use whatever satisfies them.
Who is an engineer, suggested a retrofit for the house. It seems that some of the cripple legs are rotting, and I’m hoping to make the house last another 50 years or more. My plan is to install anchor bolts, repair the legs, reinforce the cripple wall, and add brackets. I was wondering if the 6-inch bolts would be long enough.
I was wondering what made you realize that the 100-year-old house needs attention. Is it a requirement in your area?
Who is an engineer, suggested a retrofit for the house. Some of the support legs are decayed, and I want to ensure the house lasts for another 50 years or more. Therefore, I plan to install anchor bolts, repair the legs, reinforce the walls, and add brackets.
In my experience, wedge bolts are mainly used in industrial settings. We make sure to bury them as deep as possible because they can still shift 1/2-3/4″ when tightened. We typically only use them on thin plates; I’m not sure how well they would work in a residential setting.
I used these when I had to replace part of the garage sill, and they’ve held up well despite being hit by a plow a few times.
That red line indicates the minimum depth required, and the torque specification can be found on the packaging. I have used these anchors a lot, they are quite resilient. Ideally, it’s recommended to go deeper than 6 inches. However, I tend to overdo it when building or fixing things.
These are great for heavy-duty shelving. I usually go with 6 inches by 1/2 an inch. And remember, if you have an hilti store nearby, they are the pros in drilling and anchoring. Your engineer should have given you specific instructions
Just epoxy them in place and go for it. It should do the job
Is deep enough?
To the anonymous participant, make sure to leave out sufficient space to pass through your mudsill and catch all the threads in the nut.
Sometimes century-old concrete can be as soft as chalk. Hard to predict how long the building will last, but that dry coring bit cut through like butter that day.