Framing Basement Walls Against Concrete – Methods, Step by Step Guide, Tips and Tricks
The idea of framing basement walls against concrete only occurs if heyou belong to one of these.
Which gang do you belong to?
Concrete Wall is an eyesore …
…Or Concrete walls make a statement”.
You want to frame it yourself? And, you might have seen your uncle bob framing an interior wall and have an idea.
Or you may have seen the many blogs or videos out there showing step by step framing.
And now you think you are equipped to tackle this project?
You must be joking!
I agree that you know the process of framing. But, do you know the basics? Do you know the risks involved? And do you know how to frame a wall in the basement set against a concrete wall?
Make no mistake. Read this post carefully. I am going to lay down everything – all the methods, process details, risks etc.
Read and then proceed with the project.
Which Framing Methods to Use When Framing a Wall Against Concrete
What… different methods for framing?
You thought it was going to be easy right. Not with basement walls, my friend.
Like anything, you have a few options here, and a different set of pros and cons. And, a confusion as to which way to go.
While there is no set name for the methods, I am going to call it based on primary lumber type used
- Traditional Framing – using 2 x 4 lumber
- Grid Framing – using 1 x 3 lumber
Now, you never expected me to say framing using 1×3, right?
Yeah, I thought so.
Don’t worry. I am going to break it down and list down all you need to know.
Basement Framing Basics
Wouldn’t it be easier if I give you a step by step, so you know what to do when framing?
I figured so.
Here is a quick rundown of the major steps that are needed to get a wall framed.
This is more of a primer. So, you are going to be missing a thing or two here and there.
Step 1: Basement Designs, Floor Plan Permit and Engineering
Drawing and Permit
Don’t you think?
You can finish your basement without pulling a permit. Sure, no problem. But…
… You’re out of luck.
When you try to sell your house, you will be potentially dinged for the violation.
Not only that.
It makes you go to the drawing board and work and make mistakes in your paper than with the materials.
This is easy. Just draw something that closely resembles what you are planning to do.
But make sure it is to scale.
Most authorities, I have heard, accept drawings that exactly tell where your doors, windows, walls, fixtures, plumbing and such and such are.
Just draw something to scale, with all the details and submit.
It is as simple as that.
Unless… you want a complicated setup built in the basement.
That’s when you seek the help of a drafter or an architect.
Well, I doubt you are going to break open a load-bearing wall.
But, if you did, you better find a structural engineer and definitely get a permit.
You need quite a few things to start the job.
Remember the previous step is done for a reason.
If you did you work correctly, you should have all the numbers to figure out what is required.
You need the following:
Wall Studs – If you are going to have a stud every 16 inches – then use that to measure how many studs you may need.
Plates – You need a top plate and a bottom plate for all the walls.
And the bottom plate must be a pressure treated (greenish color lumber) one.
Supplies – Nails and screws
Step 3: Install Blocking to Attach Top Plate for Parallel Basement Walls
For those walls that running parallel to the joist, where are you going to nail your top plate?
Just install a block of 2-by lumber. Make sure it’s in-between the 2 joists right where the wall is going to go.
That is, between a floor joist and rim joist if this wall is backing the concrete wall.
You need to install a few of these – ideally every 16, 18 or 24 inches.
Step 4: Layout – Basement wall, Doors, and Windows
Always start with the perimeter wall and then do the interior walls
And make sure that the concrete wall is straight (A.K.A plumb). You don’t wait for any kind of bulging, or most definitely something that is not straight from top to bottom.
Now, you are thinking, how is that possible. It’s concrete right.
How do you know if the concrete subcontractor did set up a perfectly straight form?
Stop right there!
Take your leveller and make sure the wall is plumb. If not, then you should work around.
Use a chalk to snap a line where your walls are going to go. Both on the concrete floor and on the joist.
You don’t want an imperfect wall, do you?
So, adjust the chalk line if the concrete wall has imperfections.
That is if you found a wall that has a bulge and it might take another 1/2 an inch to adjust, then move the framing wall 1/2 an inch in front.
Step 5: Frame the walls
But in general, you want this setup.
A treated plate to the concrete floor nailed using the powder actuated gun. And a regular plate on top of that.
Another top plate nailed to the joists.
Then a lot of vertical studs spaced 16 inches apart.
What you want to keep in mind while framing is you need to have backer studs or plates for all the drywall screws.
It’s tricky around the inside corners and near joists.
Step 6: Frame Around Ductworks, Drain line and Obstructions
Don’t fight it. Just learn how to work around it.
Good news. Once you know, it’s basically rinse and repeat for rest of the project.
For ducts, you need to have a box built around it.
When you have a window on the concrete wall, you will have to build a frame around the window. And the vertical studs can’t go all the way from the floor to joist.
If you have a drain line or other plumbing line, make sure to run the line between the joists and where it comes down vertically, bring it between studs in on a wall.
Or if you have another kind of obstruction on your way, figure out a way to work around.
In any case, you will have to tuck it into the wall or build a box.
Remember you need to have a backing lumber for the drywall to screw down to.
Step 7: Fireblocking for safety
I don’t know about your local building authority and what they enforce. But, where I live it is code to have fire blocking in place.
Fire block is basically your 2-by lumber or a 3/4 inch plywood that fill any void or gap between the basement and the floor above.
You should come back with a fire stop or fire block rated foam to fill the smaller gaps that the 2-by wouldn’t block.
The idea is to choke the fire and smoke by isolating, that way the flame and smoke takes at least an hour to travel to the floor above. You essentially do this by compartmentalizing.
Check this blog post to learn all about fire blocking.
Framing Basement Walls Vapor Barrier
If your basement is going to have bare concrete walls, then you don’t need anything but a good bit of waterproof paint.
What if you are finishing your basement?
It’s advised to run a vapor barrier, just to make sure you don’t get any moisture issues after finishing.
By the way, you need a thermal insulation on top of that too.
Most jurisdictions require a 4-mil plastic sheet vapor barrier for basement walls against concrete. That is if the studs are going to touch the concrete wall.
Or you can leave a 4-inch gap between the studs and concrete wall and probably get away with it. So, there is enough gap for air to flow.
The codes are usually the most minimum requirement.
And I have discussed this with several experts and I always get this answer.
Bad Idea, if you just have a 4-mil poly sheet.
You must do better. Much better!
How to Frame a Basement Wall Around Pipes
First is you must assess how far the pipe is set from the basement wall.
At least couple of them will be coming off the floor and going through the ceiling.
Make sure the pipe isn’t going to be sticking out. It has to be behind the wall – that’s the idea.
The best way to save space and look nice is to tuck the pipe inside the wall.
How do you do that?
Set the wall plates just ½ inch in front of the where the pipe runs. That way the studs will be sitting ½ an inch in front of the pipe and it will be tucked in.
Can you attach drywall to concrete?
With this people usually mean, “Can drywall touch concrete?”
That doesn’t happen, my friend. You can’t.
Moisture issues from breathing porous concrete wall and basement condensation will kill it in no time.
You need framing studs to screw the drywall to.
So essentially that means you put the framing without touching the concrete or have a moisture barrier layer in between.
Then you nail the drywall into the frame you built.
Ideally, you will have a layer of foam installation and then the framing and drywall on top.
That’s the right way to go about it.
Do concrete block walls need insulation?
The biggest issue facing basement is moisture. Read this post to know more about the humidity level in the basement.
You can live with no heat, and no light in a basement, but can’t with moisture issues.
Think I’m exaggerating?
Just leave your basement above 70% relative humidity for a week and come back and see.
Or leave a basement wall weeping water and just notice what happens.
You will see mold growth everywhere. Not only that it’s going to rot the wood and it is also going to weaken the structure.
I’m not kidding.
So, you need insulation to protect your investment.
Now think about this for a second…
If you don’t insulate and if you have moisture issue behind the wall, what is going to happen is this.
You will start to have mold activity behind the drywall. Infestation will become so bad that you will have to trash all the drywall and redo it all over again.
Why don’t you do it right the first time?
What is the R-value of a concrete block wall?
The concrete block walls are porous and so you’re not going to get a lot of thermal insulation. R-value is usually between 2.21 and 2.86
It is structural material and must be always accompanied by an insulation layer.
If you have a cinder block and if the core is filled, it might have a higher R-value. So is the case with concrete block wall with insulation.
Can you spray foam basement walls?
Yes, you can. I have seen people recommending closed cell spray foam because it is considered a true vapor barrier.
However, for the benefits of open cell spray foam, that can be used. Definitely address any moistures issues separately if are going to use open cell spray foam insulation.
In any case, do NOT think of fiberglass insulation for your basement walls, especially touching the concrete wall.
Fiberglass doesn’t protect against, moisture or air.
It’s not a recommended basement insulation material. Period.
What type of insulation is best for basement walls?
However, I want to show a few different options which are either good or acceptable for basements.
Spray Foam – Closed Cell
This is the best insulation material for the basement because it has a very good R-value rating compared to many other insulation materials.
In fact, the closed cell has an R-Value of 6.5 per inch vs, 3.5 for the open cell.
Besides, because of the cell structure, it provides a nice vapor barrier.
Spray Foam – Open Cell
Open cell spray is definitely a good insulation material, but like closed cell it wouldn’t necessarily provide a vapor barrier.
Make sure to address any water issue and rectify, before using open cell insulation.
Easy to install, no mess and very DIY friendly. In fact, you can it gives a very clean look too.
There are a couple of different types of foam board. If you get a cheaper version, you need to tape it and seal to make it vapor barrier.
I have also seen other tongue and groove type, which usually locks in and once installed properly, will automatically seal it. However, taping the seams with the lock-in type foam board will work as a backup.
Just in case if there is a manufacturing defect or if you have installed it incorrectly leaving a gap.
You can go with a cheaper foamboard or spray foam on the concrete wall with a slightly lesser thickness – and save some money.
Then you can frame and insert the traditional fiberglass insulation in between the studs.
This is the least preferred method but will come out cheaper.
Word of caution: If you have an impending moisture issue, please correct that before using this option.
How to Frame a Basement Wall the Traditional Framing Way
Step 1: Insulate the Concrete Wall
For DIYers just get a good quality Styrofoam board and paste it on the wall.
When you apply the glue, do so vertically.
Did you get it? You know why I am asking you to apply vertically.
Right, you don’t want any moisture trapped behind the foam board.
If any moisture seeps in from the concrete wall, it should flow down all the way to the weeping tiles.
Step 2: Choose the Framing Installation Method
There are two schools of thought. It comes down to preference.
I prefer the first one but that needs space to work and move the frame around.
- Frame and Raise method
- Lay the frame on the floor, build it and then erect it on the concrete wall and install.
Note: I believe this method to be easier and so I am going to continue using this for reference.
- Build it in place
- Install the bottom and top plates and then start nailing the studs
Step 3: Measure and Chalk a line
Walls are made out of 2 x 4 lumber.
Do you know this?
The actual dimension of a 2 x 4 lumber is only 1 ½ inches thick by 3 ½ inches wide.
What? Yeah, right. That’s how I felt.
Find where the wall is going to go and snap a chalk line.
Since the plate is 3 ½ inches thick, you need to snap a line 4 ½ inches away from the concrete wall.
If you have foam board and then the frame, then, it’s fine for lumber to touch the foam board so you are fine with the 3 ½ inches line.
Find the right measurement at both ends of the floor and snap a line.
Repeat the same on the joists where the top plate will go.
Step 4: Measure and Cut the Needed Lumber
You need to find the length of the wall and then cut the lumber 3 ½ or 4 ½ inches smaller.
One end of the wall is going to be shorter and not touch the perpendicular wall.
You know why.
Because when you frame the other wall, it will stick out 3 ½ inches out from the concrete.
Stopping the framing 3 ½ inches short will make it just touch the other frame sharply at the edge. Assuming this is an inside corner.
Same measurement applies to the bottom and top plates
Find the height and shave 4 1/2 inches from the floor to wall height and cut all the studs.
Actually you can take off another 1/8th of an inch so when you stand the frame, you don’t wiggle too much.
You know why we are reducing 4 ½ inches. You have 3 plates measuring 1 ½ inches each.
Two bottom and 1 top plates.
And you only need to fill the gap between the joist and the floor.
Step 5: Frame the Wall
Lay the plates in such a way that the treated wood Is closer to the concrete wall.
Then lay another ordinary plate, that will sit right on top of the treated one, to form a 2 layered bottom plate.
Then use the already measured wall height and roughly place the top plate
Measure and make a mark every16 inches. On all 3 plates. This is the guide to place the studs and fasten.
If you want the studs to line up to the center of markings, make sure to mark your first 16 inches mark and then reduce half the thickness of the 2 x 4.
Remember the thickness of 2 x 4 is only 1 ½.
So, half of that is ¾ of an inch. You either measure 15 ¼ (16 – ¾) or make it easy like I do.
Measure16 inches and then reduce (i.e. come back) ¾ inches and make your first mark.
Remember to put in a check mark or X mark to know which side of the studs will be lined up with the marked line.
Then continue marking 16” from your first mark and you will be fine.
Note: Reduce 3 ½” from 16” on the side of the wall where you will leave 3 ½ inches from the wall (the perpendicular wall) and make your first mark.
Start laying the studs and fasten it to the top and bottom plate.
Step 6: Leave the Opening for Doors and Windows
When you come to the spot where you have windows or doors, leave those studs off, do not nail them to the top and bottom plates.
Once the frame is erected you can frame around them, cutting studs to length and making a precise cut and fit.
Step 7: Erect the wall in place
Move the bottom and top plates and align with the line you marked earlier
Make sure to check the wall studs for plumb.
Use the hammer to slightly tap it to get straight.
If you have a loose location between the joist and top plate, use shims to make it tight, before nailing.
You have to use a concrete driller to make pilot holes. Then use a concrete screw to fasten the bottom plate to the floor.
Or you can use a powder actuated nail gun to drive the nails into concrete and fasten the bottom plate.
Step 9: Secure the Frame to the Joists
After making sure the bottom is secure, check for plumb.
Once it’s straight up and no loose spots, nail the top plate to joists.
You will end up with 2 walls that are parallel to the joist.
For those walls, make sure to nail blocking between two joists. In this case between the rim joist and the first-floor joist.
Now, Nail the top plate to the blockings.
Voila! You are done Framing.
Not as bad as you thought right?
It’s just a matter of repeating on all walls and you would be done framing the whole basement.
Pros: Traditional method
How to Frame a Basement Wall the Grid Framing Way
It goes without saying that you need to fix any moisture issues.
You can figure out my other post on humidity and how to control.
Step 2: Insulate Concrete Wall using 2-inch Foam-Board
There are several different variations of insulating.
You can follow the steps and options given in the previous method. It all works fine.
For ease, Foam-board approach using polystyrene panels is going to work out best. Make sure to seal the joints for a true vapor barrier.
Apply Glue to the backside of the foam-board.
Again, apply it vertically so the water wouldn’t gather behind the board.
Once the glue is applied, place it on the wall and let it rest for 30 minutes so it dries.
Step 3: Mark Horizontal Lines on the Foam-Board
Once all the polystyrene panels are placed and the wall is fully insulated, start measuring.
You need 5 horizontal lines made, where you will be nailing 1×3 lumbers.
These 5 horizontal strips will compensate for the top and bottom plate and provide something for studs to nailed to.
Equally space and mark five horizontal lines using chalk reel on the foam-board.
Have one line marked 3 inches below the top of the wall and above the floor.
Then 3 lines equally spaced in between the top and the bottom line. Make sure to check for level on all lines before snapping al line.
Step 4: Attach Horizontal 1x3s to the Foam-Board and Concrete on Marked Lines
This is a very important step, and everything rests on doing this step correctly
Take a 1×3 lumber and place it on a line and start drilling, at least, 5-inch holes using concrete driller.
Remember, you foamboard will be 2 inches and the 1×3 is ¾ of an inch. For a total of 2 ¾ .
You need at least 2 more inches in the concrete for nails to have a good bite.
Once all Nail holes are drilled, go ahead and drive in concrete spring spikes to fasten all horizontal 1x3s.
These specifically designed nail heads have a small curve at the tip.
Once the nail goes into the concrete the curve gets straighter in the hole, but the tension on the nail acts as a spring creating a tight fit.
Step 5: Form a Grid Pattern by Nailing Vertical 1x3s to Horizontal ones.
Use a 1 ¾” screw, attach vertical 1x3s to horizontal 1x3s.
Make sure to screw every 16 inches at a minimum, at the center. This will form a grid pattern.
You are done, my friend.
Note: You will have enough clearance to run your electrical cables behind one or the other lumber.
As you know by now, 1 x 3 lumber is ¾ x 2 ½.
However, the depth from drywall to foamboard is only going to be the thickness of the two lumbers – that is 1 ½ inches.
The usual electric boxes (outlet boxes) are going to be 2.75 inches deep, which will make it hard to install.
So, dip into the foam board to place the outlet box.
… or figure other alternatives to bring it outside so the insulation layer is untouched.
Pros: Saves a little bit of space
Cons: Hard to drill concrete holes
Tool Box Items You Need:
I am going to list down most of the things you need.
Which is kind of common for both the methods…
|Pressure Treated 2-by-4 (2 x 4) lumber||Regular (Untreated) 2-by-4 (2×4)|
Regular 1-by-3 (1×3) lumber
|Concrete Driller||Powder actuated nail gun (optional)|
|Concrete Nails, Spring Spikes and 16d Nails||4 mil plastic (optional)|
|Measuring Tape and Square||Insulation (Foamboard and Fiberglass)|
|Chalk Reel and Pencil||Carpenter’s level (Optional: Plumb Bob)|
|Safety Glasses||Circular Saw|
That’s it. Not hard at all.
While framing entails, just putting together a matrix of 1x3s …
… or 2×4 studs between top and bottom plate, that’s not the most important.
We need to think of moisture issue and how to protect the investment.
Remembering that, and putting a pressure treated wood for bottom plate and not letting any untreated wood touch the concrete will go a long way.
Add an insulation layer -like a foam board- and think of vapor barrier. You will have a solid frame that will last for long.
There is one other thing to think about, plan, draw and perfect the plan on your paper before cutting lumber. That will save you a lot of headaches.
Planning will also help you see all obstructions and how you are going to tackle it.
If you remember these points and start working on the framing, you will be a pro in no time.
Good luck framing!