Don't bother using nylon wall plugs with aerated blocks?

[opps]

We live and learn...

I have only just discovered that a threaded screw driven straight in to a thermolite block provides a stronger fitting than a screw plus regular brown nylon plug.

https://www.wessexfixings.co.uk/news/how-to-fix-to-thermalite-durox-and-aircrete-blocks

I knew that regular brown expansion plugs are pretty useless and that aside from resin there are dedicated fixings for aerated blocks but I was surprised that the thread on a screw was better than a brown plug.

 

[foxhole]

Only plug that works in thermalite .
https://www.ebay.co.uk/i/2524219473...ULRbSgKepyaGIdw9PJQVIB05Tr9Rpb_IaApPDEALw_wcB

Rock solid .

 

[Deleted member 174758]

IMHO it depends on the size and depth of the screw. Rough though it may sound I've had success in the past first fix nailing some stuff to Thermalites........ Not that I do it that often

 

[^woody^]

I have only just discovered that a threaded screw driven straight in to a thermolite block provides a stronger fitting than a screw plus regular brown nylon plug.

Yes. A single threaded screw is best, and the deeper the thread the better. Phosphate plasterboard screws are great

The only thing is don't use a cordless, as the screw ends up spinning onces it gets in to the depth of the head and this rounds the hole off giving a loose screw.

Rawl used to make a plug called "Tap in" that was a plastic pointed thing (like a long thin witches hat) and you hit this in with a hammer and it was a nice strong fixing.

 

[mikeey84]

I've had success on thermalites with Fischer fixings. Just get the widest screws you can, and they held pretty well.

 

[Draughtsman]

Or maybe get some M6x75mm coach bolts from wilko and cut the heads off, find M6 sleeve/joing barrels online, drill 8mm holes without using hammer. Blow the holes out. Polyurethane them in. Can be a bit messy on a painted finish, masking tape around the hole might help. Keep an eye on it for 20 minutes or so bc the expanding PU will try to push the whole thing out a few mil, and you need to push it back in.

Then I used M6x12mm roofing bolts from Wilko to secure the brackets, make sure you leave enough depth in the sleeve to take the 12mm, or you'll need to add washers.

I'm putting these in for 1200x500 type 11 radiator brackets.

 

[freddiemercurystwin]

The problem I've had in this (1930's) house and the last (1900) house is that when you go to fix something into the wall you don't have a clue what you're gonna be fixing into, I recall in the last house fixing something that require about 6 mounting points on the wall and I used 4 diifferent types of fixings/plugs.

 

[cdbe]

I fixed my roof restraint straps into my durox and aircrete blocks with some of those blue concrete screws that a mate gave me. When I ran out I used 100mm wood screws. Neither with any pilot hole. I was happy enough because the pull is at 90° in my case, but they do tighten up well - but as said, you need extreme care - I used the impact driver on speed 1 and stopped as soon as it started to make that hammering sound - a millisecond too long and it's spinning round.

I did mention on another thread that I was sure I'd seen some long "plastic" hammer fixings with loads of fins for fixing insulation but I haven't been able to find them since, maybe it was a dream!

 

[catlad]

The concrete screws work, well but instead of drilling 6mm pilot hole like you would in brick use a 4mm bit for your pilot hole.

 

[Deleted member 174758]

I did mention on another thread that I was sure I'd seen some long "plastic" hammer fixings with loads of fins for fixing insulation but I haven't been able to find them since, maybe it was a dream!

You weren't dreaming:

Fischer do quite a range of them (as do several other manufacturers) to fit lightweight insulation without thermal bridging - you drill a hole with an SDS drill and a long bit, push them in and set with a hammer. They are designed to work with blockwork, though, not brickwork.

With Thermalites it is possible to fix timber battening by opposite skew nailing - two nails skewed oin opposite directions (note: requires 90mm nails, can only be done with a 1st fix nailer - not by hand, and cannot be done within about 200mm of the edge of a wall)

If you know that you are working with Thermalites (as opposed to cement blocks) there are specialist fixings which do work for them:

 

[Draughtsman]

I fixed my roof restraint straps into my durox and aircrete blocks with some of those blue concrete screws that a mate gave me. When I ran out I used 100mm wood screws. Neither with any pilot hole. I was happy enough because the pull is at 90° in my case, but they do tighten up well - but as said, you need extreme care - I used the impact driver on speed 1 and stopped as soon as it started to make that hammering sound - a millisecond too long and it's spinning round.

It does make the fixing into aerated blocks so much easier if the pull is at 90° (in shear).

 

[ericmark]

But plastic plugs melt in a fire, so thought we have to use metal ones now? At least inside a building where the cables etc they hold into place can fall off and get entangled in a fire fighters BA equipment.

Gone are the days of sticky back T2 trunking and finish with sealant, as the sticky back lost stickyness so the sealant dried and held instead. Today it is plastic to make it look good, but every so often metal so will not fall off in a fire.

 

[Deleted member 174758]

But plastic plugs melt in a fire, so thought we have to use metal ones now? At least inside a building where the cables etc they hold into place can fall off and get entangled in a fire fighters BA equipment

I work more on commercial builds, and in my environment I've seen ever increasing use of concrete nailers with metal fixings for electrical wiring and plumbing over the last 8 or maybe 10 years.

 

[ericmark]

I think the latest edition of BS 7671 has made it plain the difference in escape route and designated escape route, it now seems it may only apply to the latter, i.e. where you have concrete walls and stairs with no carpet or paint which can burn, but the fire regulations are not easy to understand, metal consumer units and the like and even metal lids on them, does seem some times to be going OTT, specially since metal conducts so remove one risk but replace it with another.

 

[Draughtsman]

Or maybe get some 75mm M6 coach bolts from wilko and cut the heads off, find M6 sleeves online, drill 8mm holes without using hammer. Blow the holes out. Polyurethane them in. Can be a bit messy on a painted finish, masking tape around the hole might help. Keep an eye on it for 20 minutes or so bc the expanding PU will try to push the whole thing out a few mil, and you need to push it back in.

I'm putting these in for 1200x500 type 11 radiator brackets.

Alternatively, maybe I could have just carefully drilled, and Gorilla glued some 80mm wood dowels in.