Advice on building a stud wall on concrete floor

[London1986]

First question is around screws... Do I use concrete/masonry screws (the ones that don't require wall plugs) or regular screws with wall plugs.

Second question is regarding screwing the wood/sole plate straight onto concrete - Does it need to be treated or a protection layer in-between the sole plate and floor to prevent any potential moisture rising up the wall?

[Another project]

I've used both concrete screw's and regular screw's and wall plugs they're both fine. I personally wouldn't bother with a moisture barrier as you'll have to drill holes in it to secure the base plate. If I was concerned about moisture I'd use treated timber just to be sure

[loughran]

I use Fischer frame fixings, they're available in different lengths.

https://www.screwfix.com/p/fischer-sxr-l-t-nylon-f...

If you're concerned about moisture then use a DPC and silicone the fixing holes.

https://www.screwfix.com/p/capital-valley-plastics...

[London1986]

loughran said:

I use Fischer frame fixings, they're available in different lengths.

https://www.screwfix.com/p/fischer-sxr-l-t-nylon-f...

If you're concerned about moisture then use a DPC and silicone the fixing holes.

https://www.screwfix.com/p/capital-valley-plastics...

Thanks a lot for this. I may not need it but for less than a fiver, that DPC is a no-brainer.

I did have a look at those frame fixings before but they're not cheap!

I didn't want to use regular screws with wall plugs as it would mean I need to mark my sole plate first (and upright which is going against a masonry wall) and then move it, drill hole, move back in place, making sure its exactly aligned, then screw in... seems a bit of a faff.

This is why I was drawn to concrete screws... what do you think of these? https://www.screwfix.com/p/easydrive-tx-countersun... Only concern it mentions on there for light to medium duty fixings

[London1986]

I found these cheaper alternatives which should also do the trick?

https://www.screwfix.com/p/fischer-nylon-hammerfix...

[Pflanzgarten]

Use your concrete screws (that don’t need plugs) 6mm masonary bit straight through the sole plate then dugga dugga the screw in with your impact driver. Remember room and out your masonary hole to get all the dust out or the screw won’t go in enough (an air tube blower helps)z

As for damp, where is your damp proof? I lay a 150mm subfloor over my damp proof layer so I know I can screw in 100mm without penetrating it

[London1986]

Ok update...

Just tried these screws - https://www.screwfix.com/p/easydrive-tx-countersun...

No good. As I mentioned it did state for light and medium duty fixings.. I should have listened! Didn't seem very secure at all. So I've returned that and now going to try these https://www.screwfix.com/p/fischer-nylon-hammerfix...

All the other concrete screws are fully threaded so want to avoid them

[London1986]

Pflanzgarten said:

As for damp, where is your damp proof? I lay a 150mm subfloor over my damp proof layer so I know I can screw in 100mm without penetrating it

I am not sure. How would I find out?

[Pflanzgarten]

London1986 said:

Pflanzgarten said:

As for damp, where is your damp proof? I lay a 150mm subfloor over my damp proof layer so I know I can screw in 100mm without penetrating it

I am not sure. How would I find out?

We'll need more info than you've provided.

[Pflanzgarten]

London1986 said:

Ok update...

Just tried these screws - https://www.screwfix.com/p/easydrive-tx-countersun...

No good. As I mentioned it did state for light and medium duty fixings.. I should have listened! Didn't seem very secure at all. So I've returned that and now going to try these https://www.screwfix.com/p/fischer-nylon-hammerfix...

All the other concrete screws are fully threaded so want to avoid them

https://www.screwfix.com/p/easydrive-tx-countersunk-concrete-screws-7-5-x-150mm-100-pack/7465h

This is what you want, drill a 6mm hole straight through your sole plate.

[London1986]

Pflanzgarten said:

https://www.screwfix.com/p/easydrive-tx-countersun...

This is what you want, drill a 6mm hole straight through your sole plate.

Yes saw those, but I've been advised to avoid fully threaded screws as they have too much bite which isn't ideal for soft wood stud work

[b0rk]

London1986 said:

Ok update...

Just tried these screws - https://www.screwfix.com/p/easydrive-tx-countersun...

No good. As I mentioned it did state for light and medium duty fixings.. I should have listened! Didn't seem very secure at all. So I've returned that and now going to try these https://www.screwfix.com/p/fischer-nylon-hammerfix...

All the other concrete screws are fully threaded so want to avoid them

Just an FYI but with concrete screws the hole you drill should be 1mm narrower than the screw, so 6mm screw = 5mm drill bit, 7mm screw = 6mm drill bit, if the hole you drill is to wide the screw won't bite into the concrete.

Nothing wrong with fully threaded screws, these will normally have a smaller head and rely on the thread to clamp the material rather than the screw head. The "over bite" issue will be screw "jacking" in the softwood this happens when you don't apply enough pressure on the wood to stop the screw from "rising up". Basically just stand on the sole plate as you use your dugga dugga.

[jrb43]

Not really sure what too much bite is but obviously you want to draw the wood down onto the concrete. If you're worried, drill an oversize hole in the sole plate and add a washer?

Second the advice to really clean the hole out, I used those screwfix screws for a shed and they were somewhat hit and miss. Which must be all about my technique because the reviews are rave.

TBH, can't think when I'll next use them so if you DM me and make it really straightforward, I'll send you some?

[Baldchap]

I always pilot the wood, use a Marksman to mark the holes, drill @7mm and Rawl plug, then a nice big torx screw. Do that all the way round to create a solid frame, then go from there. Solid as a rock.

Problem with some direct concrete fixings is they can be very aggressive. Pre-drilling and using a plug takes the potentially damaging element out of the equation.

[neth27]

London1986 said:

Thanks a lot for this. I may not need it but for less than a fiver, that DPC is a no-brainer.

I did have a look at those frame fixings before but they're not cheap!

I didn't want to use regular screws with wall plugs as it would mean I need to mark my sole plate first (and upright which is going against a masonry wall) and then move it, drill hole, move back in place, making sure its exactly aligned, then screw in... seems a bit of a faff.

This is why I was drawn to concrete screws... what do you think of these? https://www.screwfix.com/p/easydrive-tx-countersun... Only concern it mentions on there for light to medium duty fixings

Just use screws and plugs. You don’t need to mark a hole then move it. Drill the hole through the timber and concrete. Push the wall plug in to the hole in the timber and knock in with a hammer. Then put your screw in the wall plug and hammer it all into the concrete.

[CharlesElliott]

neth27 said:

Just use screws and plugs. You don’t need to mark a hole then move it. Drill the hole through the timber and concrete. Push the wall plug in to the hole in the timber and knock in with a hammer. Then put your screw in the wall plug and hammer it all into the concrete.

^This

[Pflanzgarten]

CharlesElliott said:

neth27 said:

Just use screws and plugs. You don’t need to mark a hole then move it. Drill the hole through the timber and concrete. Push the wall plug in to the hole in the timber and knock in with a hammer. Then put your screw in the wall plug and hammer it all into the concrete.

^This

Torque head concrete screws are even simpler, no plugs no hammer

[Chumley.mouse]

Is hammering a plug in not simple ?

[neth27]

Pflanzgarten said:

Torque head concrete screws are even simpler, no plugs no hammer

I would rather use screws and plugs, you don’t need to pull the drill bit in and out 10 times to remove all the dust with screws and plugs. I use concrete screws to fit windows but not really for anything else.

[Pflanzgarten]

neth27 said:

Pflanzgarten said:

Torque head concrete screws are even simpler, no plugs no hammer

I would rather use screws and plugs, you don’t need to pull the drill bit in and out 10 times to remove all the dust with screws and plugs. I use concrete screws to fit windows but not really for anything else.

I find a decent masonry bit and you don't have to either, two or three times maybe and only when drilling down. I use them for everything now.