# Help - Installing Drywall over Brick



## rookiebathroomremodeler (Mar 29, 2021)

I am in the middle of a bathroom remodel and have run into a problem while instaling drywall in my 1890 brick townhome.  My contractor removed the drywall on the lower half of an exterior wall to replace the existing drywall with a moisture/mold resistant drywall prior to tiling.  The existing drywall was not actually attached to the brick wall behind it - instead it was mortared onto the brick wall and then wedged into/caulked into the corners to hold it in place.  Now that we have removed that old drywall, what do we need to do to install new drywall?  The brick wall is a very soft brick that crumbles easily when you try to drill into it.   Also- will we now be required by code to add insulation?  We don't have the option to build out the wall with framing because it is a small bathroom and the sink drain is exactly 15 inches from the existing wall - and there's no room to move it. 

Our plan is to install plywood that will be screwed into the brick if possible (this section of the wall is only about 3 feet wide x 4 feet high) and then install drywall onto the plywood.  Otherwise there is nothing to screw the drywall to to pass the screw inspection.  I'd also like to not have to add insulation as the existing brick wall didn't have any issues and there is no room for making the wall thicker than it already is.  Can we just do what the last people did?

Any thoughts or advice about what to do?  And about whether we will run into code issues now that this section of wall is opened up?


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## ICE (Mar 29, 2021)

Drywall can be glued to the brick.  Might use HardieBacker instead of drywall.  I doubt that an inspector would be concerned with such a small area.


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## rookiebathroomremodeler (Mar 29, 2021)

Hi Ice. Thanks for responding! Gluing to the brick would be the easiest and makes the most sense to me.  But is that OK for code?


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## Teeshot (Mar 29, 2021)

If the brick surface is relatively flat, gluing would be the simplest method, especially for such a small area. If it is rough, the drywall may not attach properly and the roughness may telegraph through the drywall. You may want to seal the brick first so moisture does not seep through since it's an exterior wall. If it is rough, you should scrape as needed to flatten as best possible, otherwise, installing furring strips is the typical method of attaching drywall to brick, concrete, etc.


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## rookiebathroomremodeler (Mar 29, 2021)

Thank you for the response Teeshot - really helpful!

My contractor was concerned that the inspector would make him install insulation in the wall now that it is opened up. Is this not a concern?  We also won't have the right screw pattern if we just glue it, is that OK?


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## Teeshot (Mar 29, 2021)

For such a small area, installing insulation would not accomplish very much if the remainder of the wall is also not insulated. As for the minimum screw pattern, most inspectors will approve field conditions based on unique circumstances, this being one. The safe route is to always check with the inspector first, before moving forward so you don't get stuck doing things twice.


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## ADAguy (Mar 29, 2021)

Is this a single or double course brick?


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## cda (Mar 29, 2021)

rookiebathroomremodeler said:


> I am in the middle of a bathroom remodel and have run into a problem while instaling drywall in my 1890 brick townhome.  My contractor removed the drywall on the lower half of an exterior wall to replace the existing drywall with a moisture/mold resistant drywall prior to tiling.  The existing drywall was not actually attached to the brick wall behind it - instead it was mortared onto the brick wall and then wedged into/caulked into the corners to hold it in place.  Now that we have removed that old drywall, what do we need to do to install new drywall?  The brick wall is a very soft brick that crumbles easily when you try to drill into it.   Also- will we now be required by code to add insulation?  We don't have the option to build out the wall with framing because it is a small bathroom and the sink drain is exactly 15 inches from the existing wall - and there's no room to move it.
> 
> Our plan is to install plywood that will be screwed into the brick if possible (this section of the wall is only about 3 feet wide x 4 feet high) and then install drywall onto the plywood.  Otherwise there is nothing to screw the drywall to to pass the screw inspection.  I'd also like to not have to add insulation as the existing brick wall didn't have any issues and there is no room for making the wall thicker than it already is.  Can we just do what the last people did?
> 
> Any thoughts or advice about what to do?  And about whether we will run into code issues now that this section of wall is opened up?



Exterior or interior wall??


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## Rick18071 (Mar 29, 2021)

Plaster the wall.
Code only requires the voids to be filled with insulation on existing houses. If no void no insulation required. But even if you could fit a 1/2" of foam it would help keep the bathroom warmer.


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## rookiebathroomremodeler (Mar 29, 2021)

The wall is on the inside of the house, but its an exterior brick wall. I believe it is actually triple course brick.


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## cda (Mar 29, 2021)

Maybe use Concrete board ???

Mortar of something that will last ?? To hold it


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## cda (Mar 29, 2021)

Youtube


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## rookiebathroomremodeler (Mar 29, 2021)

I am going to suggest the cement board over the brick instead of drywall, and hopefully it can be mortared or glued on.  I did see that video on Youtube - but unfortunately I don't have nice hard brick like that guy has, mine tends to crumble when you try to screw anything to it.


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## rookiebathroomremodeler (Mar 30, 2021)

I had the other contractor who is working on this project come by today to look at the wall. He suggested using brick mortar to float the wall and then tile directly to the mortar.  I think that is the plan for now.


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## cda (Mar 30, 2021)

rookiebathroomremodeler said:


> I had the other contractor who is working on this project come by today to look at the wall. He suggested using brick mortar to float the wall and then tile directly to the mortar.  I think that is the plan for now.




Not a Tile GUY, but does not like a good idea.


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## ADAguy (Mar 30, 2021)

Brick without rebar will expand and shrink over time, popping the tiles.


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## north star (Mar 30, 2021)

*@ @ > >*

*Rookie,*

*Have you actually spoken with the Inspector for ideas ?
IMO, ...if possible, I would not attach anything to the
brick.......From your description, it sounds too soft and
fragile to attach anything to it.

What is the distance from the face of the brick, that
you have to work with ?....Also, to possibly increase
the overall soundness of the brick wall, can you apply
a coat or coats of some type of heavy duty, adhesive,
then a thin layer of Hardieboard........It does come in 
1/4" thicknesses.*

*< < @ @*


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## rookiebathroomremodeler (Mar 30, 2021)

Unfortunately it's nearly impossible to get ahold of an inspector here and voicemails don't get returned.  I have now removed some of the plaster that was between the old drywall and the brick and the brick is in pretty good shape from what I can tell (though still too soft to reliably drill into). I'm actually considering just exposing it on that whole wall (5 feet wide wall).  I have exposed brick on the same wall on the lower level of my house already and it looks really nice. The other idea is to attach some 1x1s horizonatally across the wall from the window to the stud on the sidewall and screw the drywall into that. I agree that mortaring that wall is sounding like a bad idea.


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