Bathroom framing with storage above

[joshua5438]

Hello all. I am about to start the framing for a bathroom in my 30x50 shop. The bathroom is 9'-8" long by 6'-4" wide (out / out). It will have four wood stud walls and will be on a 5" slab floor. I plan to frame the wall as traditional (bottom plate, studs at 16"oc, double top plate). I will likely add some cross bracing between the studs for rigidity. The bathroom will have an 8' ceiling height. My plan is to build "knee walls" from the top of the room to the bottom of the ceiling with an opening on one side. This area will be used for storage. The room will only be attached to the floor as none of the walls will tie back to the steel building or the roof. Here are my questions...

1 - What is the best way to attach the bottom plate to the concrete floor (any specific brands or sizes for anchors)?
2 - I know it is overkill to but is it bad to span the ceiling/floor joist in the short span (6'-4")? I figure this will help distribute the load and really does not add all that much cost.
3 - Should I use 2x8 or 2x10 for my joist at 16"oc?
4 - Would a double layer of plywood for the storage floor provide any benefits since the spans are so short?
5 - The bathroom entrance door will be on the short span, 6'-4". Would it be beneficial to make the door header as if it's a load bearing wall or is that just wasting money?

I don't plan to store a lot of really heavy items in this space but I also realize weight adds up quickly when trying to use up a small storage space. Any other suggestions, questions or comments would be greatly appreciated also.

Below is a plan of the bathroom layout.

 

[dcg9381]

> 1 - What is the best way to attach the bottom plate to the concrete floor (any specific brands or sizes for anchors)?

Here, we just use a Ramset .22 caliber to put a nail into the concrete. You can get them at most hardware stores.

> I know it is overkill to but is it bad to span the ceiling/floor joist in the short span (6'-4")? I figure this will help distribute the load and really does not add all that much cost.

No. It's not bad. You can use an 8' board instead of a 10' board. With as crazy as lumber is, it might be less even with double the spans.

> Should I use 2x8 or 2x10 for my joist at 16"oc?

I defer to span tables here. Depends on what you are putting up there.

> Would a double layer of plywood for the storage floor provide any benefits since the spans are so short?

Depends on what you are putting up there. I'm most familiar with OSB that is setup to be flooring. It's like 1-1/8th thick. Look at Huber's AdvanTech. You won't need much. It also interlocks.


> The bathroom entrance door will be on the short span, 6'-4". Would it be beneficial to make the door header as if it's a load bearing wall or is that just wasting money?

I would treat it like it's load bearing. It is, to some degree... But it's just a knee wall 2nd story with no roof load, so YMMV. I wouldn't go nuts.

 

[joshua5438]

I looked at an online calculator and it appears that I could span 9'-10" with a 2x8 at 16"oc figuring 100psf Live Load and 10psf Dead Load. 100psf was the max the calculator allows. With me spanning 6'-4" I feel it should hold anything I decide to load it with, within reason. haha.

 

[firebirdparts]

that is a tiny span. Look at your joist tables. It doesn't take much. If you span the short way, then you won't need a header over the door.

 

[thammel]

Smart move putting in a shower. I wish I did, in retrospect. I also put a storage area above my small powder room. I just used 2x4 for the ceiling joists at 16" centers. Span is only about 3 feet. Then 3/4 OSB for floor of storage area. I even found a panasonic exhaust fan that fits in the 3 1/2" space up top between the powder room ceiling and OSB floor. I put a light up there and it's totally enclosed with a little access door - use a ladder to get to it. It's a good use of otherwise wasted space.

 

[joshua5438]

Thanks for the info. I think I will go with 2x8 at 16"oc. Still looking at options for the wall to concrete. The Ramset is a good idea but $100 for the gun is steep for something I will likely never use again. I may just bolt it down. for the flooring.. I may just go with 1/2" plywood and double it up. Still come out cheaper than OSB at this point. I think that would be plenty sturdy for a storage floor. Thoughts?

 

[ddawg16]

Quick rule of thumb on span's (aprox)....1"/ft.

So...8' span...2x8....10' span....2x10

But nothing wrong with using span tables.

I wouldn't bother with cross bracing. The drywall alone in the bathroom will provide plenty of bracing.

I would suggest a vent fan or maybe a window assuming it's attached to the wall of the garage. You really don't want your methane emissions going into the garage. And the humidity from the shower can create issues over time.

 

[Innovate1]

For the floor attachment tapcons work well. Just need a hammer drill and screw them in. There are faster methods but for a couple walls the extra time isn't that much.

I agree with Firebirdparts. Run the joists the 6' way and you don't need a door heavy door header - it will just hold the door frame. The span is less too. I did something similar here and used 2 x 6 joists. They meet the loading for the short span with standard loads. I also extended them 2' beyond the wall for a little more storage and but a light under for the bench below.

3/4" or double 1/2" should be plenty for flooring.

I would tie the outside wall at the top (or the upper floor) to the building or use plywood or osb on one side of the walls. That gives more resistance to the walls collapsing by tipping over.

 

[nadogail]

I agree with shooting the plate down to the slab, I find it easier and quicker than using Tapcons.

 

[joshua5438]

An exhaust fan is on my list of needed items. haha.

I am trying not to tie the room to the steel structure. Not sure what I would use to connect them if I did. I will likely cover the wall between the room and the wall with plywood as I want to insulate all four walls. This way the insulation is not against the metal building as I know will sweat at some point. The remaining walls will be covered in drywall.

 

[NUTTSGT]

Personally, I would use 2x8s and frame across the short span. Buy 14 footers and cut them in half. Then run your OSB, perpendicular so it spans more ceiling/floor joists.

Secondly, I would turn both sinks 90° so they are back to back. That will allow use of the same drain line and supply lines.

Third, where are you located ? If you're in an area that get cold winters, you don't want to put your plumbing in an outside wall. Consider flipping your plan to a mirror image. Unless of course, you already have all the plumbing in place and concrete poured. I would still make an effort to keep the plumbing out of the cold exterior walls.

 

[joshua5438]

Personally, I would use 2x8s and frame across the short span. Buy 14 footers and cut them in half. Then run your OSB, perpendicular so it spans more ceiling/floor joists.

Secondly, I would turn both sinks 90° so they are back to back. That will allow use of the same drain line and supply lines.

Third, where are you located ? If you're in an area that get cold winters, you don't want to put your plumbing in an outside wall. Consider flipping your plan to a mirror image. Unless of course, you already have all the plumbing in place and concrete poured. I would still make an effort to keep the plumbing out of the cold exterior walls.

All plumbing rough ins are already set and concrete poured. Code does not allow a bathroom sink and utility sink to share a drain. That is what I have been advised by local plumbers. This only added one additional drain and then the supply lines that will be ran inside the wood stud walls. The way I am planning to frame is the "exterior" wall of the bathroom will be butted against the exterior wall of the garage. So it will have the metal wall as a buffer and then I will insulate the bathroom exterior wall. Not sure if it would be a good idea to try and insulate against the steel exterior wall as it may want to sweat. I live in the upstate of SC so plumbing on an exterior wall is common practice.

 

[The Tool Tyrant]

You should also consider balloon framing all walls to the bottom of your roof structure, then ledger the 8' ceiling /storage area. This eliminates the hinge points at the wall/ceiling point.
Depending on the amount of stored weight you're planning, you may want to shear the walls.

I would use 3/4" T&G on the storage rather than double 1/2"

 

[joshua5438]

I understand balloon framing but not sure what you are referring to for "shear the walls". I know what a shear wall is/does but what would I do differently to make these walls deflect shear?

 

[dcg9381]

The Ramset is a good idea but $100 for the gun is steep for something I will likely never use again. I may just bolt it down. for the flooring.. I may just go with 1/2" plywood and double it up. Still come out cheaper than OSB at this point. I think that would be plenty sturdy for a storage floor. Thoughts?

I think home depot rents these things. At my HD so a single shot ramset is $30. Bolting (drilling) is a lot more work and a hammer drill is a lot more expensive.

Double ply would be fine, but the advatage of that advantec stuff is that its T&G. There may be other options.

 

[pcmeiners]

Minor addition...
In the shower area if using tile, use old straight 2x4s" if possible as new or even kiln dried wood shrinks .

"At my HD so a single shot ramset is $30."
I have used this model and they really ****, anything is better than this.

 

[joshua5438]

I will look if renting in available. I already own a hammer drill.

 

[The Tool Tyrant]

I understand balloon framing but not sure what you are referring to for "shear the walls". I know what a shear wall is/does but what would I do differently to make these walls deflect shear?

Just means make the walls "shear walls". Each plywood / OSB panel MUST be boundary nailed to create a diaphragm, so edge block accordingly. The more weight stored above the ceiling, the more critical proper anchorage to the slab becomes. Since you already own a roto-hammer, you can use wedge-bolts (red-heads) to anchor to your slab.

 

[joshua5438]

Just means make the walls "shear walls". Each plywood / OSB panel MUST be boundary nailed to create a diaphragm, so edge block accordingly. The more weight stored above the ceiling, the more critical proper anchorage to the slab becomes. Since you already own a roto-hammer, you can use wedge-bolts (red-heads) to anchor to your slab.

So the plywood is only nailed about the exterior edge? I would assume it would be best to run the panels vertical and add a stud where needed for nailing? Would I need to wrap all four walls with plywood?

I am thinking an anchor every 2' should be sufficient?

 

[The Tool Tyrant]

They must also be nailed 'in the field'. Nailing schedules vary depending on engineering requirements. For what you are doing, you'd be safe nailing with 8d's at 6"o/c boundary and 10" in the field.
You can run shear panels in either direction, so pick which direction requires the least amount of additional blocking. You can get 3/8" struct I ply in 4x8 or 4x10 panels, so you have some choice on options.
If you are not anchoring to the roof or structural walls, I would shear all 4 walls...but that's me. Some may say the sheetrock is sufficient, which it may suffice...but do you want to take the chance?

 

[joshua5438]

By "either direction" I take it vertical or horizontal, correct? Would this need to be on all four walls of the room?

 

[Innovate1]

I will look if renting in available. I already own a hammer drill.

By the time you find where you can get a rental I could be done drilling and using tapcons for a small space like this.

 

[joshua5438]

By the time you find where you can get a rental I could be done drilling and using tapcons for a small space like this.

What size and spacing do you recommend if I use tapcons?

 

[The Tool Tyrant]

By "either direction" I take it vertical or horizontal, correct? Would this need to be on all four walls of the room?

Yes and yes. If you are going to the trouble to shear the walls, go with wedge anchors as their holding power is much higher than Tapcons. I would install 6" from each wall end and opening, then every 32" (every other bay).

 

[joshua5438]

Yes and yes. If you are going to the trouble to shear the walls, go with wedge anchors as their holding power is much higher than Tapcons. I would install 6" from each wall end and opening, then every 32" (every other bay).

Thanks. I just noticed the last part of your reply above about all four walls. I just know how quickly weight adds up with storage. Especially with car parts. I dont intend to pack it full but I do want to feel safe when it does have a lot in it.

 

[FordTruckWench]

5 - The bathroom entrance door will be on the short span, 6'-4". Would it be beneficial to make the door header as if it's a load bearing wall or is that just wasting money?

In recent decades, I've observed pros putting a header across any wall opening, even if it is not a load bearing wall. For a narrow opening like your doorway, a 4x6 seems to be enough.

You never know how things are going to be remodeled in the future! I think it has also been deemed that neither drywall nor stucco have enough strength to bridge an opening on their own.

 

[Innovate1]

In recent decades, I've observed pros putting a header across any wall opening, even if it is not a load bearing wall. For a narrow opening like your doorway, a 4x6 seems to be enough.

You never know how things are going to be remodeled in the future! I think it has also been deemed that neither drywall nor stucco have enough strength to bridge an opening on their own.

4 x 6 for a bathroom door in a wall that is not load bearing is rediculous. It just needs to be solid enough and tall enough to hold the nails for the door casing. Two 2x4s with a spacer between to make them 3.5" thick would be plenty.

 

[joshua5438]

I am thinking I may have enough left over 2x8 from the joist if I plan it out right. If I do, I will throw those above the door. If not, I will just do the 2x4's. All of the load is going into the two solid walls. I do appreciate all of the opinions though. Everyone has one and it's always good to hear as many as you can before you make your own call. Like making all the walls shearwalls. I had not considered that but with more research I have convinced myself to do it. Especially since this will be a free standing room with storage above.

 

[NUTTSGT]

4 x 6 for a bathroom door in a wall that is not load bearing is rediculous. It just needs to be solid enough and tall enough to hold the nails for the door casing. Two 2x4s with a spacer between to make them 3.5" thick would be plenty.

He's in Cali, they build to a slightly different code out there for earthquake stuff.

 

[The Tool Tyrant]

If you really want to get technical, even though his joist are running in the short (4'-6") direction, being as the floor plywood will also bear on the two short end walls...they become bearing.
Guessing the door is a 2'-4" door (33" header) a 4X4 would be sufficient.

 

[Innovate1]

If you really want to get technical, even though his joist are running in the short (4'-6") direction, being as the floor plywood will bear in the two short end walls...they become bearing.
Guessing the door is a 2'-4" door (33" header) a 4X4 would be sufficient.

I still say that wall isn't load bearing. The floor plywood sits on the joists. The joist may or may not put weight on the wall depending on how tight a fit the carpenter made but the joist is sufficient to hold up the floor (and the joist being supported by other walls at the ends) making the wall, technically, not load bearing.

 

[joshua5438]

I still say that wall isn't load bearing. The floor plywood sits on the joists. The joist may or may not put weight on the wall depending on how tight a fit the carpenter made but the joist is sufficient to hold up the floor (and the joist being supported by other walls at the ends) making the wall, technically, not load bearing.

I deal with precast concrete everyday. This is always a "battle" to prove the other wrong. haha. I do agree, that just because something is one top and likely carrying some weight, it does not make it a load bearing wall. I can honestly see the argument on either side but when a educated engineer explains it, it all makes since, and that I am not. In theory, the end wall should be able to be removed without affecting the support of the roof/floor support.

 

[NUTTSGT]

So what does it take to make it a non-load bearing door opening ? Half a 8' 2x4. What do you do with the other half ? Flip it on edge along with a scrap of 1/2" wall sheathing and make it a load bearing opening.

 

[Joemctag]

You didn't ask, but if you're using a corner shower as shown, they're sized to a code minimum and you can't bend over to wash your legs without hitting the wall or glass door. Unless you're a child, I guess. I'd go with a 5 foot long shower on the left wall. Plumbing same location. May have to move drain some. Honeycomb concrete with hammer drill and chip out. Not a big deal. Have to have a wall at "south" end of shower unless you get a base that has that side open. You might wish you'd put in a small window. To make it nicer. Not anything you can't do. Have to cut metal siding and use flashing.
Also, I'm sure you'll have something to keep items from falling into the gap between the new wall and the bldg wall.