HELP: Crumbly wall and Concrete Screws???

[ItsTony]

Hi,

I'm using concrete screws for the first time in what I think is a breezeblock wall. The wall is part of a warehouse and runs two storeys high and from the looks of it has a supporting beam on so I'm assuming it should be quite strong but just drilling into the wall I can tell it is very soft. After then putting the masonary bit in I can literally pull it out with the thread just crumbling.

Is my pilot hole too big, or are these breezeblocks not actually breezeblocks and may just be thermalite blocks or something else so concrete screws aren't suited to it.

Also, what is the alternative - will a regular 4 inch hammer fixing plug be able to give similar strength to a concrete screw or is the block too crumbly to use.

Thanks.

[Ricky_M]

Try drilling with a smaller bit. Use a 6mm drill bit for a brown plug for example, will take a bit of a tap to get it in, but should give you better bite.

Thermalites are a nightmare for a decent fixing, but you can do it.

ETA- Not sure what you mean by concrete screws, so my advice may be bks!

Edited by Ricky_M on Saturday 2nd October 21:04

[ItsTony]

These are the concrete screws a friend recommended. They don't need plugs and only require a pilot hole but the thermalite blocks way too crumbly and it just pulls straight out. Think I'll go down some sort of plug and screw route - only question is which one, lol.

http://www.efixings.com/home.php?cat=324

[Wings]

Ricky_M said:

Try drilling with a smaller bit. Use a 6mm drill bit for a brown plug for example, will take a bit of a tap to get it in, but should give you better bite.

Thermalites are a nightmare for a decent fixing, but you can do it.

ETA- Not sure what you mean by concrete screws, so my advice may be bks!

Edited by Ricky_M on Saturday 2nd October 21:04

+1 agree, longer length of screw, possibly hammer in type fixing.

[Mr GrimNasty]

Have you tried screwing in with no pilot hole at all & making sure you stop as soon as it is home?

[ItsTony]

It's always crumbly whatever I use. I can use a screw directly in, on the very lowest speed setting on my drill and it drives in absolutely no problem.

Just tried some hammer type fixings with plug but they still don't really feel that strong, although its only about 3-4cm thats being held in the wall - the rest is holding up a 3x2 length of wood on the wall.

[Plotloss]

I've never had the guts to use multi-montis

We use proper rawls.

[Simpo Two]

Ah well I'd say that the problem is that the screws are concrete, which is very hard, and you're using them in breezeblock, which is very soft...

Try 100+mm window frame fixings. Drill the appropriate hole, place the wood, wallop the fixing right in with a hammer then finish off with a screwdriver.

http://www.screwfix.com/search.do;jsessionid=G03AT...

Edited by Simpo Two on Sunday 3rd October 07:11

[cjs]

Try switching the hammer off on the drill, always do this when drilling into Thermolite blocks. You should get a good fixing using Brown plugs and normal wood screws, try using two brown plugs.

[Spudler]

Ricky_M said:

Try drilling with a smaller bit. Use a 6mm drill bit for a brown plug for example, will take a bit of a tap to get it in, but should give you better bite.

Thermalites are a nightmare for a decent fixing, but you can do it.

This^^ and what cjs has suggested. The drill must be held very steady, any movement (other than straight in & out) will enlargen the hole. Obvious..but the hole must be dust free.

[Mr GrimNasty]

If it's really that difficult you could resort to the expensive option - resin fixings!