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Structure: Supporting the house from the basement

Our house had numerous structural problems, many (but not all) of which were the result of bad DIY by the previous owner. This post is part of a series outlining what we did to correct these problems.

Our house had several structural issues that overwhelmed me as a do-it-yourselfer. I am not ashamed to admit that I turned to the pros for help. We had been living for years without use of our second floor. On the main floor, I had gutted the ensuite bathroom. And we knew we had to replace a supporting wall that the previous owner had removed.

We consulted with an architect and hired a couple of contractors to renovate and restore our house. The contractors started in the basement. When dealing with structure, start at the lowest point and work up. Structure is only as good as the support under it.

Sagging load-bearing joists

First of all, it is important to note that a load bearing block wall divides the basement into a workroom area and a recreation room area. In the workroom, below the bedroom and bathroom, the double joists which supported load bearing walls above had sagged significantly. The contractors’ first course of action was to support the joists from below and bring them up to level.

jack posts
Three jack-posts were needed to get rid of the 3/4″ sag in this double joist.  The posts were replaced by a stud wall.

Using a few jack posts, they cranked up the joist until it was level. They then built a stud wall underneath.

stud wall
The new stud wall

The new stud walls in the basement carry the load above and divide the workroom into three rooms. These walls also serve as the walls of the new basement bathroom which is directly under the original location of the main floor bathroom.

framing the bathroom walls
The framing for the bathroom walls helps support the structure above.

Jacking up the joists did cause some damage on main and second floors as the movement resulted in cracks to drywall and plaster. This was to be expected. And it really wasn’t a problem. We were going to completely gut the main floor on this side of the house anyway. And the damage to the second floor wasn’t anything some drywall compound and paint wouldn’t fix. A few cracks in the wall now is preferable to more damage in the future.

stress cracks
The resulting stress crack in the drywall.

Support Beam

In the recreation room portion of the basement, a main beam runs the length of the room. Well, not quite the entire length. The problem here was that the beam stopped at the chimney, leaving another 8 feet or so unsupported. We already removed the chimney to just below the level of the second floor a few years ago. So I had the contractors remove the rest of it. With the chimney completely gone, they could continue the beam across the rest of that portion of the basement.

support beam and stud wall
The new section of the main support beam, supported by a 2×6 stud wall.

A new 2×6 stud wall helps support the beam where the new section meets the old section. The wall replaces the one that was there previously, and encloses the boiler room.

The Basement Window

The previous owner had penchant for installing oversized windows with no regard for the structure around them. Another glaring example of that was the basement window. He replaced a typical basement window with a picture window. The larger window allowed a lot of light into the basement and providing beautiful view of the picturesque back yard. However, outside there was no lintel to support the bricks above the window. And inside, he had sacrificed the support for the floor joists and framing. To make matters even worse, the window was right at ground level. Without a window well, the wood frame had suffered extensive water damage and the window was prone to leaking.

installing a lintel above a window
A steel angle iron lintel was installed to support the bricks.

The solution was to remove the old window, which was near the end of its life anyhow. The contractors built up the ledge several inches with poured concrete, raising the new window above the ground. Outside, they notched the bricks on either side of the window and installed an angle iron lintel to support the brickwork. Aluminum capping was installed later. Inside, another angle iron, supported by wood studs, supports the floor joists.

new basement window
Concrete was added to the block to raise the window off the ground, creating a smaller window opening.

Structural Repairs: How to “unbutcher” a house

The Back Dormer: Repairing water damage and fixing framing problems
The Back Dormer:  Adding ventilation and eliminating water leaks
The Sunken Tub
Supporting a house from the basement up
Load-bearing walls



  1. clayton johnson

    Will 5 2x10s be enough to carry the load on a load bearing wall for 16 feet in a one story ranch, I plan to sister 2 more 2x10s onto the three I already have with structural adhesive and remove one support post?

  2. Thumb and Hammer

    I am neither an architect nor a structural engineer so therefore I am not going to attempt to give you an answer. If you are going to be messing around with any kind of structure at all, you really should talk to your local building department and spend the money for a proper permit and inspection. Not only for your own peace of mind, but also for the future value of your house when it comes time to sell.

    Trust me. All you have to do is take a look around this website and see what I had to go through to make things right after the previous owner’s renovations.

    I suppose you could say that technically he “got away with” royally screwing up the structural integrity of the house because it didn’t collapse. But it could have. Or at least there could have been more serious damage.

    At least YOU know that you have to compensate for removing a support post. But to find out exactly what you need to do you should consult the experts.

    That said, you could call your building department and ask their opinion about what you are “THINKING” of doing, you know, hypothetically speaking. You might get some guidance that way. But when you are talking about load bearing, there are no doubt calculations to determine the amount of the load that has to be carried as well as how to carry that load.

    And as if this (non) answer isn’t long-winded enough, I will add one more point. On his radio show on CJAD Montreal, Jon Eakes often points out that during the massive ice storm in 1998, the roofs that collapsed were the ones where supporting walls had been removed inside.

    • Thumb and Hammer

      Our repair was spec’d out by an architect. I asked the same question myself. He explained that the load is spread out along the length of the wall. Usually in basements, the load is concentrated on posts. In that case, it would most likely be necessary to bust out some of the concrete slab in order to pour a footing for the post.

    • Thumb and Hammer

      It’s difficult to say. We had 2-3 general contractors on-site for close to 3 months doing these repairs and other renovations in the house. The architect/project manager gave us the “friends and family” discount (most of his services were free, but there would have been a cost for the specs plus a 5% project management fee otherwise). I’m not sure how much the steel lintel cost, but the other materials, except for the concrete and new window, were simply dimensional lumber.

      The repairs in the basement (featured on this page) probably took 2-3 days. Ballpark estimate is probably somewhere around $1000 to 1500, mostly labor. This doesn’t include the bathroom, only the framing. Also remember that this work was done in 2009.

      The main floor was more complicated because now we’re talking about demolition, framing, remodeling (we changed the layout) plus all finishing materials (drywall, flooring, trim etc).

      As a general rule, the structure itself isn’t very expensive. The major cost comes from disruption to the finished living spaces.

  3. don

    Putting up support posts in basement under sagging main beams, the main beams are uneven and slant a little inwards. So the support posts are plumb using a 14 inch red oak hardwood and hardwood shims on top. Will this still be in code.

    • Thumb and Hammer

      This may be something you should have a structural engineer evaluate if you are concerned about the integrity of your main beams. Your setup might be fine for what you are trying to accomplish, or it might not. It will depend on the compressive strength of the shims. There might be another material that will work better, and additional reinforcement might be necessary to prevent further sagging and twisting of the beam.

      As for your concerns about meeting building code standards, one would assume that your house was built to code in the first place. So unless you are replacing existing supports, then I doubt that adding new supports wouldn’t change that. And if you are replacing existing supports, then you really should consult with an engineer or building inspector.

      From what I’ve found doing a cursory search, you can expect an engineering assessment to cost in the neighborhood of $500. That’s a little painful but might be worth it for peace of mind.

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