How do you repair a stem wall?

we sprung a leak under our house and found lots of damage including the stem wall was rotted out on 2 walls. all other fixes are easy but not sure how to fix the stem wall our selves.

  3 answers
  • Debbie King Debbie King on Jul 04, 2018
    I remember seeing this very thing on Mike Does It Right. A long time ago. Mike owns a construction crew in Canada and they get the back story on botched jobs that homeowners are stuck living with and he explains what and how it should have been done. I am sure you could find that episode online and have it to refer to in all confidence it would be a successful job well done in the end as you do it yourself to his specifications.

  • Pmr33619375 Pmr33619375 on Jul 04, 2018
    Since you haven't mentioned the age of your home, I'm not sure that you are using the correct terminology. A stem wall is below ground wall that sits on top of a footer. Typically they are made of concrete or cinder block. You mentioned that the stem wall is "rotted" out on two walls. Using the term rotted could mean that the concrete/cinder blocks have broken down, or it could be that the sill plate that sits on top of the wall is rotted, which I guess is what you are talking about.

    In either case you are talking about a major repair job, best left to professionals for a number of reasons. The repair will involve having to use at least four house jacks and two cross beams. Unless you know exactly what you are doing, you could easily crack the walls inside your home. If professionals do the work, make sure they are covered by insurance and that you have this possibility covered in your contract with them.

    Basically two or more holes are cut into the wall where a cross beam is inserted. A house jack is then placed at each end of the beams. The beams are then raised to support the wall. Determining the correct pressure that the beams apply to the wall is generally based on experience and knowledge. Once the beams are in place the rotted material is removed and replaced with new material.

    In the case of a stem wall, this would involve constructing forms for the concrete, installing rebar, and pouring strength enhanced concrete.

    In the case of a sill plate, this would involve removing the rotted wood, cutting out any bolts/nails and, if done properly, drilling holes for new bolts. Once the prep work is done, the new sill plate will have to be sized and drilled for the retaining bolts. There are several ways that the new sill plate will be installed. Regardless cement will have to be poured into the bold holes and the sill plate with bolts immediately installed.

    Depending on how this repair is done, some siding or brick may have to be removed and replaced.

    I suggest getting the input of several reputable contractors. Make sure that they have actual experience in making these repairs. A botched job can put the whole house in jeopardy.

    Phil Rasmussen
    The Mountain Woodworker
    Hendersonville, NC

  • Sparkles Sparkles on Jul 04, 2018
    Thank you for your replies. This may be more than we can do our selves. ):

    It is an older home. built in the 1960's. The foundation is cinder blocks, and you are correct it is the sill plate. (my mistake)

    In fixing the leak we found wood rot, termite damage and water damage.
    This is when we discovered the sill plate damage.

    We have gutted the room floor to ceiling, pulling down the paneling and sheet rock. Pull down the ceiling tiles. Taken out the floors and replace floor joists under the house.

    The siding may have to come off about 4 rows high or more? Windows need replaced at some point. Hoping not to crack or break them while doing the other work.