Hemlock mudsill foundation

h2obreathe

Hi,
I'm new to the forum and new to construction. I have hired this real oldtimer carpenter (semi-retired) to assist me in building an 8x12 mudroom attached to my kitchen door on the rear of my house. We are actually building the mudroom right inside the rotten walls of the old mudroom, which was bigger.

After cutting out the old floor and ceiling, we realized the ground level inside this old structure is about a foot below the level of the ground outside, and my old-timer helper decided we'll put a 8x8 12 ft hemlock mudsill right on the ground, shim it up with bricks and rocks underneath, and hang floor joists. We don't have any holes with concrete piles or pressure treated posts or anything. My helper insists that as long as we provide fill and drainage around the outside of the mudsill, we will not get any frost heaving.

I am having some concerns about this "old school" style of building, but this guy seems pretty sure.

Any thoughts?

Maintenance 6

There are some very specific, accepted methods for wooden foundations. That ain't one of them. What you are proposing doesn't come close to meeting any sort of building code. Just the fact that you need to be concerned with frost heave tells me there is sufficient moisture in the earth to cause a problem. If the last mud room rotted away, what do you think this one will do?

h2obreathe

Thanks for your response. I think the last mudroom rotted away because there was no drip edge on roof, and the interior walls were drywall. Also, The old mudroom extended across the propery line (grandfathered), very close to the edge of the house next door, so there was very little air circulation.

Maybe you are right and it's not up to code.

Think I can jack up what I've built so far and dig a couple post holes?

Thanks.

Brik

There needs to be a proper foundation/footer. This is dug to below the frost line. The first step is to remove the old addition. In may area of the country the footers are 4 feet below grade to prevent frost heave. There may be other techniques. Your building code people will be able to tell you what is required in your area.