Prep exposed wall for painting

[dannyrus]

Hi folks! First time poster here

I'm doing a DIY bathroom reno and just yanked the old medicine cabinet off the wall... I expected to see exposed bricks but there's this concretey grey stuff on top of the bricks (that I assume is the same adhesive behind the tiles themselves?).

I need to mount the new medicine cabinet in this spot but unsure what to do with this section, so my question is do I need to seal/paint/fill in the bricks and old adhesive first?

The new cabinet is larger than the hole left by the old one, see the third image below with the outline of where the new one will sit.

Massive thanks in advance for any advice!

Cheers Danny.

[Jason]

Hi @dannyrus,

Great to see you make your first post. Thanks for joining in the discussion. We are looking forward to seeing how your bathroom renovation progresses. Maybe you could share some before and after images in a new discussion? 

I'm sure Workshop members will be happy to help with your question about whether you need to do any preparation before mounting the cabinet. I might help if you provide a little more information, though. For example, I see that there's a shower next to the cabinet. Do you expect any water to hit it? Is there any sign of any previous issues that you might need to address?

Welcome to the community,

Jason

[dannyrus]

Hey Jason!

Thanks for the welcome - happy to do a before and after, great idea (taking lots of photos along the way)

Yep for some additional info, there will be a shower screen going up to stop the water so it shouldn't have any direct water near it... as far as previous issues, nothing that I can see really - structurally everything is solid and no signs of mould or damage other than that section of concrete missing from the bottom of the gap, but it seems that was missing before the previous cabinet went up as none of it broke away when I removed it.

I was mostly just checking in here whether I can safely prime and paint over the concrete, and whether anything should be done about that gap (and what if so). Eg, since it'll be hidden behind the cabinet, is "No More Gaps" sufficient to fill in the space and just level the area, or is something more robust recommended...

Hope that's a little clearer - I apologise for all my newbie-ness

Thanks heaps, Danny.

[Jason]

Hi again @dannyrus, 

Thanks for the update. Let me tag a couple of our most valued contributors in @ProjectPete and @Adam_W for you - I'm sure they would be able to offer some advice.

Thanks for your patience,

Jason

[Simon]

Hi @dannyrus,

I would apply a primer sealer onto the exposed concrete. Two coats would be better, 1 litre of paint should be plenty.
All paint brands have their own version of this product, save yourself the hassle and choose a water based sealer. These can be applied directly onto the brickwork. Give the surface a once over it with a brush to remove any loose dirt and make sure the surface is dry before painting.

Also, you're correct in applying a No More Gaps between the new cabinet and the wall. There are a couple of brands to pick from, each of which have specific 'wet area' products within their range. These come as white or some are paintable too.

Hope this helps!

[ProjectPete]

Welcome @dannyrus.The good news is, with the new cabinet being bigger than original, you don't have the pesky job of  patching/smoothing for a clean finish around the cabinet.

I agree with @Simon. I'd fill any actual gaps/holes in the cement/bricks to prevent moisture build up then seal over it - two coats. Once the new cabinet is on the wall, seal the edges with a wet area silicone colour to match your cabinet/wall (or just go with clear) and you should be done.

[dannyrus]

@Simon & @ProjectPete - superb, thanks a mill for this! It's all been on hold for a few days so I'll pick this up again on the weekend.

One more newbie question if I can - the new cabinet is around 30kg's and I've been advised to attach a couple pieces of wood to the exposed area (in the photo) then screw the new cabinet into those... my question is how do I go about holding the cabinet in place while I drill it all in? I've seen a video of a guy using a "cabinet jack" but I don't have one of those lying around any tips?

Thanks a bunch again.

[ProjectPete]

Of course you can!

Simplest way is usually to just use some lengths of timber (offcuts) or books, bricks, etc. Just remember to protect your basin/benchtop first!