Fixings for MF to block and beam ceiling

[Thorfun]

Thinking ahead. Creating a false ceiling in the basement using MF and will need to fix to the blocks in the block and beam ceiling. I will put 100mm Rockwool above and hang 19mm Gyproc plank and 12.5mm standard plasterboard underneath. so that will be quite a weight at about 28kg/m2. 
 

i’m planning on using MF12 soffit cleats and FEA1 folded angles as my hangers for the MF7 and MF5 ceiling sections. 
 

what’s the best fixings to make sure things stay up?

 

Concrete screws? Rawl plugs and wood screws? Something special?

 

and how far in to the blocks should the maximum be? I.e. fixing length. 

[Conor]

Our boarders used a nail gun. Don't know if it's the best, but fast and nothing has moved  they were something like 20mm nails with a plastic sheath, fired from a massive gas gun.

[nod]

I fix to the underside of floors regularly The spec is nearly always Tech screws Fully metal knock ins are quick and you can hang an elephant off them But twice the cost of Tech screws 

[Oz07]

1 hour ago, nod said:

I fix to the underside of floors regularly The spec is nearly always Tech screws Fully metal knock ins are quick and you can hang an elephant off them But twice the cost of Tech screws 

Links? Or pics?

[Thorfun]

1 hour ago, nod said:

I fix to the underside of floors regularly The spec is nearly always Tech screws Fully metal knock ins are quick and you can hang an elephant off them But twice the cost of Tech screws 

 

13 minutes ago, Oz07 said:

Links? Or pics?

Found this on Google https://www.fastco.co.uk/blog/what-are-tek-screws/ but it suggests that they’re used to screw in to metal. @nod how do these work in to blocks? 

[Thorfun]

Interestingly I found a link the TIMco nail-in anchors (https://timco.co.uk/0640ZNA-zamac-nail-in-anchors-zinc) and it states

 

”NOTE: Not recommended for overhead applications such as suspended ceilings.”

[nod]

42 minutes ago, Thorfun said:

 

Found this on Google https://www.fastco.co.uk/blog/what-are-tek-screws/ but it suggests that they’re used to screw in to metal. @nod how do these work in to blocks? 

If you use Tek screws You need Blues Threaded to the point 

Don’t use anything with plastic on them Nails are no good to the underside Unless you can fire hangers into the sides Something like Trapazoids 

[Thorfun]

3 hours ago, nod said:

If you use Tek screws You need Blues Threaded to the point 

sometimes @nod I need a translator to understand what you mean! luckily, these days we have ChatGPT.

 

Quote

The phrase "If you use Tek screws, you need Blues threaded to the point" seems to refer to two important elements when using Tek screws for fastening metal to a block ceiling:

1. Tek Screws: These are self-drilling screws designed to drill into metal without needing a pilot hole. They are commonly used for fastening metal panels or other metal components to a surface. The tip of the screw has a drill-like point that allows it to penetrate metal or masonry.

2. Blues Threaded to the Point: This likely refers to the blue-coated Tek screws, where "blue" is the color associated with the coating or treatment on the screw that helps resist corrosion, particularly in outdoor or exposed environments. "Threaded to the point" means that the screw’s threads extend all the way to the tip, which ensures better grip and penetration, especially into materials like metal or masonry.

So, putting it together: the phrase seems to advise that when using Tek screws, you should use screws that are blue-coated(for corrosion resistance), and that are fully threaded to the point to ensure they properly grip and penetrate the material you're fastening, whether it's metal or a block ceiling.

 

so, using that information do you mean something like this? https://www.toolstation.com/dewalt-tapper-pro-blue-hex-head-self-tapping-screws/p86871 and this https://www.fastbuildsupplies.co.uk/tapcon-hex-head-screw?child_id=5019&gad_source=1&gbraid=0AAAAADLDIQF58tKyCzXVc2eAGcaNGrnBw&gclid=EAIaIQobChMIofe35fvliQMVk6VQBh0h3BhqEAQYAyABEgKu2vD_BwE

 

and I know they say self-tapping but surely that's not in to concrete, right? so drill a hole in the block and use these to fix the MF in to the block?

[Nickfromwales]

15 hours ago, Thorfun said:

Thinking ahead. Creating a false ceiling in the basement using MF and will need to fix to the blocks in the block and beam ceiling. I will put 100mm Rockwool above and hang 19mm Gyproc plank and 12.5mm standard plasterboard underneath. so that will be quite a weight at about 28kg/m2. 
 

i’m planning on using MF12 soffit cleats and FEA1 folded angles as my hangers for the MF7 and MF5 ceiling sections. 
 

what’s the best fixings to make sure things stay up?

 

Concrete screws? Rawl plugs and wood screws? Something special?

 

and how far in to the blocks should the maximum be? I.e. fixing length. 

Use a gas nailer. My Spit gun earned its £500 price tag on one job in 3 days.

When are you doing this job? If you cover P&P you can borrow mine? 
Fixings aren’t cheap, but the time saving/ease of use is insane.

[Thorfun]

33 minutes ago, Nickfromwales said:

Use a gas nailer. My Spit gun earned its £500 price tag on one job in 3 days.

When are you doing this job? If you cover P&P you can borrow mine? 
Fixings aren’t cheap, but the time saving/ease of use is insane.

I have a friend with a Spit gun I’ve borrowed before but thank you for the offer. My concern is the force of the nailer and any potential effect on the finished flooring on the floor above. 
 

there’s about 50mm EPS, ufh pipes in 50mm Cemfloor screed, then porcelain tiles. 
 

For the sake of time I would be extremely gutted if the vibrations did anything to damage the tiles. 

[saveasteading]

17 minutes ago, Thorfun said:

any potential effect on the finished flooring

None. Otherwise what is it doing to your hand and arm, which are talking the exact same force?

[Thorfun]

11 minutes ago, saveasteading said:

None. Otherwise what is it doing to your hand and arm, which are talking the exact same force?

ahhh....Newton's 3rd law.

 

i got an E in my physics A-level.

 

but my body has lots of soft and squidgy bits that can absorb forces so definitely not as rigid as a solid floor above!

[Nickfromwales]

47 minutes ago, Thorfun said:

I have a friend with a Spit gun I’ve borrowed before but thank you for the offer. My concern is the force of the nailer and any potential effect on the finished flooring on the floor above. 
 

there’s about 50mm EPS, ufh pipes in 50mm Cemfloor screed, then porcelain tiles. 
 

For the sake of time I would be extremely gutted if the vibrations did anything to damage the tiles. 

My dear Watson. It won’t do anything of the sort! 
“Fire away”. Blocks will absorb and dissipate the impact. 

[Thorfun]

5 minutes ago, Nickfromwales said:

My dear Watson. It won’t do anything of the sort! 
“Fire away”. Blocks will absorb and dissipate the impact. 

thanks. are you able to link suitable fixings please? my mate has a Paslode Spit P370 Spitfire.

[Thorfun]

@Nickfromwales would it be these standard single-shot concrete pins? https://www.kelvinpowertools.com/spit-50mm-single-shot-concrete-and-stone-pins-for-p370-100pk-c-550-p-7815

 

if so, how come there's conflicting info between yourself and @nod as he said

 

5 hours ago, nod said:

Nails are no good to the underside Unless you can fire hangers into the side

 

it's all so confusing. 😞 

[Thorfun]

also, i'm going to use MF12 soffit cleats (https://www.buildingmaterials.co.uk/british-gypsum-gypframe-mf12-soffit-cleat-box-of-100?mh_keyword=&mh_matchtype=&mh_adgroupid=&mh_network=x&utm_term=&utm_campaign=pMAX:AllChannels|CatchAll&mh_campaignid=18789495083&gad_source=1&gclid=EAIaIQobChMI-_33sZnmiQMVGqRQBh3JeAMpEAQYASABEgIN-PD_BwE)

 

i think trying to accurately nail through the hole is going to be fraught with danger!

 

 

i'm really thinking a nice safe drill and concrete screw will be better for me as a DIYer.

 

it's just needing to translate @nod and his blue tip tek screws. 😉 

[saveasteading]

1 hour ago, Thorfun said:

my body has lots of soft and squidgy bits

Perhaps not as much as mine. I find using even  a normal nail gun into timber to be unpleasant and scary. I remember using a hilti gun into concrete with equal displeasure and somd failures. It's a skill. So I also would drill, plug and screw.

[Thorfun]

3 minutes ago, saveasteading said:

Perhaps not as much as mine. I find using even  a normal nail gun into timber to be unpleasant and scary. I remember using a hilti gun into concrete with equal displeasure and somd failures. It's a skill. So I also would drill, plug and screw.

i am heading that way just without the plug i'm thinking.

 

i've no issues with the Spit gun. used it before to fit timber to steels and it was fine.

[nod]

[Thorfun]

9 minutes ago, nod said:

thanks. that looks like a rather sharp point on that thing! much sharper than the other concrete screws i've seen.

 

but, regardless, definitely looks like a concrete screw so those blue ones i linked before should do the trick.

 

 

drill a hole and screw in, right?

 

if i go for 50mm screws is that excessive? the photo of yours looks shorter than that.

[Gone West]

2 hours ago, Thorfun said:

I know they say self-tapping but surely that's not in to concrete, right?

Product Details

One-piece self-tapping concrete screw with ICC-ES Approval. For use in a variety of base materials including wood. Coated in a corrosion resistant Perma-Seal coating with an optimised thread design for low installation torque. Also incorporates a gimlet drill point for wood, no pre-drilling required.

[Thorfun]

15 minutes ago, Gone West said:

Product Details

One-piece self-tapping concrete screw with ICC-ES Approval. For use in a variety of base materials including wood. Coated in a corrosion resistant Perma-Seal coating with an optimised thread design for low installation torque. Also incorporates a gimlet drill point for wood, no pre-drilling required.

struggling to believe that a screw can self-tap in to concrete! i guess i'll have to buy some and give it a go.

[Gone West]

1 minute ago, Thorfun said:

struggling to believe that a screw can self-tap in to concrete! i guess i'll have to buy some and give it a go.

Last year I used concrete screws to fix some timber to a concrete block wall. They are very sensitive to the hole being exactly the right size.

[Thorfun]

1 minute ago, Gone West said:

Last year I used concrete screws to fix some timber to a concrete block wall. They are very sensitive to the hole being exactly the right size.

yes. exactly, right? you drilled a hole and then screwed the concrete screw in? that's what i've done before as well.

 

i guess i'm completely misunderstanding the meaning of "self-tapping". i thought it means you don't have to drill a hole but that's not true is it? you drill the hole and then the self-tapping screw creates the thread that holds it in to the hole, right?

 

i'm such a twonk sometimes. 🤦‍♂️

[Oz07]

How do blocks take to being sds drilled when used in transverse on b and b floor. I'd be a little concerned it would crack. Sure I'm worrying about nothing, you'd soon get a feel for it