Attach ventilation grille to foundation wall.

[Screew]

I need to mount ventilation grilles on the vents to the crawl space. The surface of the foundation is very uneven and rough, and my initial thought was to drill/screw and then seal with some sort of caulk. The problem is that it is impossible to drill correctly and straight due to the concrete containing many larger stones. Now I'm considering if it would be a sensible solution to attach them with stone adhesive or something similar instead. Would that work? I'd like the uneven surfaces to be well filled so that no animals can get through.

 

[jonaserik]

Stone adhesive may not adhere very well to a metal valve, but it will surely hold it in place. Insert the valve, see how big the gap is, apply a thick bead, and press the valve in so it oozes over a bit. After a while, you can use a knife to cut away the excess. It's good to place a stick between the ground and the valve, for support, so it doesn't move/sink before it has set.

 

[Screew]

Stone adhesive might not adhere well to a metal valve, but it will certainly hold it in place. Insert the valve, see how large the gap is, apply a thick bead and press in the valve so it oozes out a bit. After a while, you can use a knife to cut away the excess. It's good to use a stick between the ground and the valve for support so it doesn't shift/sink before it sets.

Unfortunately, the holes are not suitable, I can't insert the variant with the edge. So a flat grate is needed, but is there any kind of adhesive that works outdoors and adheres to both plaster/concrete and metal?

 

[useless]

Mortar/plaster?

 

[jonaserik]

The holes are unfortunately not sensible, I can't fit the variant with the edge. So it's a flat grid that applies, but is there any form of glue that works outdoors that adheres to both plaster/concrete and metal?

PL 400 sticks to almost everything. Don't forget to rig so they don't sink. The grid will sink before PL has cured, own weight.

 

[Claes Sörmland]

I need to mount ventilation grilles on the vents to the crawl space. The surface of the foundation is very uneven and rough, my initial thought was to drill/screw and then seal with some joint. The problem is that it is impossible to drill correctly and straight as the concrete contains many larger stones. Now I'm considering if it is a reasonable solution to attach them with stone glue or something similar instead. Would that work? I would like the unevenness to be filled out well, so no animals can get through.

If you drill with a hammer drill, you'll go straight through any granite.

I struggled for a long time with impact drills and other crap, but a Jula hammer drill after recommendation here and now I almost look forward to the chance to drill into concrete and stone...

 

[Screew]

PL 400 grips almost everything. Don't forget to rig them so they don't sink. The grid will sink before the PL has cured, due to its own weight.

I'll check if it works, it should also fill in well on the irregularities.

If you drill with a hammer drill, you go straight through any granite.

I struggled for a long time with hammer drills and other crap, but a Jula hammer drill after recommendation here and now I almost look forward to the chance to drill in concrete and stone...

I have a Dewalt hammer drill, maybe I should try with a new drill. The house is about 100 years old and the concrete contains a lot of aggregate which causes problems. But maybe I can try again. Normally, it's possible to drill straight and nicely into concrete with that machine.

 

[Screew]

Wall-/plaster mortar?

I don't know, guessing some form of plaster mortar over the concrete.

 

[Claes Sörmland]

I'll check if it works, it should also fill in well on the unevenness.

I have a DeWalt rotary hammer, I might try it with a new drill bit. The house is about 100 years old and the concrete contains a lot of aggregate which causes problems. But maybe I can try again. Normally, it is possible to drill straight and nicely into concrete with that machine.

I have the same problem, basement from 1920, as much granite as concrete. Concrete was probably expensive back then... I use a red Jula rotary hammer. It looks like this but an earlier model. So around 9 J in power:

https://www.jula.se/catalog/verktyg...TkYLG-TaaJJuE8nhva0dq13XVmWTZeOBoCmtkQAvD_BwE

 

[Plupp 405730]

Will check if it works, it should also fill out well on the irregularities.

I have a Dewalt rotary hammer, maybe I should try with a new drill. The house is about 100 years old and the concrete contains a lot of ballast, which causes problems. But maybe I can try again. Normally, you can drill straight and nicely into concrete with that machine.

Start by making a smaller hole because if you have concrete hollow block in your foundation, the hole can easily become too large... You can saw in with a small angle grinder with a diamond blade intended for concrete, so you know it won't crack improperly when you then drill...

 

[Screew]

Thank you for all the tips, I have 3 ventilation grills to install. I’ll try and see what works best. I’ll also see if I can rent a slightly more powerful machine than the one I have.

 

[Plupp 405730]

Start with what you have because it might be enough.

 

[jonaserik]

Thanks for all the tips, I have 3 ventilation grilles to install. I'll try and see what works best. I'll also see if I can rent a slightly more powerful machine than the one I have

If it's a machine that sounds like a dental drill, don't press hard, otherwise the drill will turn blue at the tip.

 

[Screew]

It is a https://www.proffsmagasinet.se/mask...H9D_b7MDhd-bSt6NWN2TO36_lGrRbVHhoCgIwQAvD_BwE

It sounds like a real impact drill and works well in regular concrete without lots of large stones in it.

If it is a machine that sounds like a dental drill, don't press hard, as the drill will turn blue at the tip.