Basement Wall Construction

Written by admin

Basement Wall Construction

Basement Wall and Basement Floor To evaluate basement waterproofing options, it helps to have a basic understanding of how different foundations can leak Not all basements are created equal. This is mainly due to the different materials used to construct the foundation walls that define the basement. Each of the four foundation types described below has unique characteristics that should be considered when designing a basement waterproofing system. The one universal factor in any basement waterproofing plan is the poor performance of exterior drainage systems. Even though many houses have footing drains as shown in the drawings, these drains don’t perform well if at all. The drains are easily crushed during the backfilling process. A well-functioning exterior drain will eventually clog with silt and plant roots, rendering it useless. POURED CONCRETE WALLS typically leak along the joint between the floor and the wall. High hydrostatic pressure outside the foundation can cause water to seep through solid concrete walls. It will also force water into the basement along the crack between the floor and the walls. Cracks that form in walls also provide pathways for water to enter the basement. CONCRETE BLOCK WALLS will leak along the floor/wall joint, just like poured concrete walls. But the mortar joints between individual concrete blocks also have the potential to leak. Pressure against a concrete block foundation often weakens mortar joints, causing cracks that allow water to penetrate. The hollow cores in concrete blocks can fill with water, causing the foundation to leak long after the soil outside the house has dried out. Expect the same characteristics of cinder block walls. STONE WALLS are found primarily on older houses. Because stone masons may not have had the time, materials or skill to construct long-lasting waterproof walls, ground water can seep or even flow into the basement through gaps or cracks between stones. An interior perimeter drain system is necessary to capture water that leaks though walls as well as water that leaks through the floor/wall joint. CLAY TILE WALLS are found on some historic houses. The floor/wall joist is a common leak location. So are the mortar joints between clay tiles. Like concrete blocks, clay tiles have hollow cores that can become filled with water, creating a reservoir of water that can leak into the basement over time. Because clay tile is brittle and more easily damaged than other masonry materials, care must be taken when working on this type of wall. The bottom line: It’s smart to install an interior French drain system Because every type of basement foundation can have water leaking through walls as well as along the floor-wall joint, any waterproofing system should aim to capture this leakage before it can get onto the basement floor. The WaterGuard® system from Basement Systems is designed to perform these dual collection tasks flawlessly. NextLesson Next Lesson Footing Drain – Ineffective Drainage Previous Lesson Previous Lesson Hydrostatic Pressure on Basement Walls Looking for a price? Get a no cost, no obligation free estimate.
basement wall construction 1

Basement Wall Construction

Basement construction with concrete block is quite common. It will produce a strong basement in most locales. Concrete block tends to be the most economical way to build a basement. You’ll have many more concrete masons to bid the job than sub-contractors who can do poured concrete basement construction. The competition tends to produce lower prices. However, concrete block, even if reinforced, is not appropriate for areas that have expansive soil. That’s soil that swells a lot when it gets wet and shrinks when it dries. The swelling of this soil will apply lateral loads (pressures) to your basement wall (push on it sideways) and can actually cause the basement construction to crack and fail. If this is your soil type, you’ll need reinforced concrete basement walls. Again, the local Building Code or a geotechnical or soils engineer can help you determine this.
basement wall construction 2

Basement Wall Construction

If the level of the soil outside your basement (it’s called the finished grade) is higher than your basement floor, you are said to have an “unbalanced backfill” condition If the height of the unbalanced backfill is less than four feet, your basement construction can be done with a simple unreinforced, 8” block wall. If the unbalanced backfill is up to five feet, you’ll need a 12” block wall. If it’s up to six feet, you’ll need a 12” concrete block wall that is filled solid with grout or built with solid block units. If the unbalanced fill is higher than that, you will need additional steel reinforcing. Remember, these are merely rough rules of thumb. Your local Building Code can give you specific requirements for basement construction in your location. It’s always a good idea to consult with a structural engineer to make sure your foundation and basement are structurally sound and comply with the codes.
basement wall construction 3

Basement Wall Construction

POURED CONCRETE WALLS typically leak along the joint between the floor and the wall. High hydrostatic pressure outside the foundation can cause water to seep through solid concrete walls. It will also force water into the basement along the crack between the floor and the walls. Cracks that form in walls also provide pathways for water to enter the basement. CONCRETE BLOCK WALLS will leak along the floor/wall joint, just like poured concrete walls. But the mortar joints between individual concrete blocks also have the potential to leak. Pressure against a concrete block foundation often weakens mortar joints, causing cracks that allow water to penetrate. The hollow cores in concrete blocks can fill with water, causing the foundation to leak long after the soil outside the house has dried out. Expect the same characteristics of cinder block walls. STONE WALLS are found primarily on older houses. Because stone masons may not have had the time, materials or skill to construct long-lasting waterproof walls, ground water can seep or even flow into the basement through gaps or cracks between stones. An interior perimeter drain system is necessary to capture water that leaks though walls as well as water that leaks through the floor/wall joint. CLAY TILE WALLS are found on some historic houses. The floor/wall joist is a common leak location. So are the mortar joints between clay tiles. Like concrete blocks, clay tiles have hollow cores that can become filled with water, creating a reservoir of water that can leak into the basement over time. Because clay tile is brittle and more easily damaged than other masonry materials, care must be taken when working on this type of wall.
basement wall construction 4

Basement Wall Construction

When framing in a basement, it is perfectly fine to build a wall on the ground and you will not have to shim the wall. The reason for this? A floating wall, due to settling/movement of the foundation slab. So for a basement, build your wall before putting it into place. You will end up gluing and nailing a 2×4 on the concrete that will help hold your floating wall in place. You will want about a 2-3″ gap between the bottom of your floating wall and the top of the 2×4 on the concrete slab. Then, you drill holes every 32″ through the bottom plate of your floating wall and hammer 1/2″ x 5″ long nails through these holes into the 2×4 on the slab. Now you have a floating wall!
basement wall construction 5

Basement Wall Construction

This was great information for starting on finishing our basement, but I’m really apprehensive about attaching the bottom plate. I would really rather not compromise the concrete floor for fear of water seeping up through. We have a very old home and something I’ve never seen in our basement. There is a 2inch wide trough around the perimeter of the whole basement. We have been here 3 year, had some rather significant rain and snow fall and never had standing water in the basement, sometimes the trough has a little water in it but never enough to overflow. It really seems like a pretty clever way of keeping any water out of the basement but kind of puzzles me about working around it to put up exterior walls. Do you think it’s ok just to place the wall a few inches in front of the trough? Is it possible to NOT attach the bottom plate?
basement wall construction 6

Basement Wall Construction

8 Steps to build a wall in place for your basementLine up the top and bottom plates and mark where the studs need to go, starting from the end make a mark every 16″.  (check your local code to see if this differs but 16″ on center is fairly standard). Don’t worry if you forget this step, you can measure each seperately, this just makes it easier.Nail your top plate to the ceiling joist. You may need some “blocking” if your top plates is parallel to the joists. If you’re working solo like I was then use a couple of quick-grip clamps to hold the top plate in place while you position it and secure it.Plumb down to the floor and mark two points for your bottom plate. Use a chaulk line to snap a line between these two points. Your snapped line will run parallel to the wall.Place your bottom plate on the floor and line it up on the line you just snapped.  Even though you don’t have any vertical studs in place at this point your top and bottom plates should be almost perfectly aligned.  DON’T NAIL IN YOUR BOTTOM PLATE JUST YET.Cut and install a stud (a vertical board for the wall) into the top and bottom plates.  The stud should fit snug in between the top and bottom. It should be able to stand up on its on.  If you have to really hammer on it to get it in then it’s probably to long. Take it down and trim a small amount off.Repeat step 5 until all of the studs are in place.  You may have less than 16″ between the last two boards, that’s okay.Take your 4′ level and double check that the wall is plumb (up and down) and relatively flush on the service.  By flush I mean that none of the studs are bowed so much that they stick out further than the other studs.  If they do then you’ll have a hump in your drywall and your wall will look wavy.  A bowed stud who’s hump goes towards the wall is better, the drywall will still be straight on the outside.Nail your bottom plate into the floor. I recommend a concrete masonry gun. Mainly because it uses tiny little bullets and you basically have a gun in your basement, very cool.  You may see some videos/books where they glue it down first, I didn’t do that.  Mainly because I messed up a lot at first and needed to be able to move the wall a bit.  The contractors I consulted with said it was not a big deal to skip it (for a basement project).

Basement Wall Construction

Leave a Reply

Your email address will not be published. Required fields are marked *