Thermal block fixings

[CD]

I've had a google & looked at the FAQ but can't find a deal.. I am under orders to put up 3 wall units today, these will go on the outside wall which is done in those lightweight blocks that aren't breeze blocks. Standard Rawplugs just spin in these due to the crumbly nature of them. I fear Rawbolts will just crumble the blocks when they expand. Screwfix or B&Q are my only options.

Thanks

CD

[Tim S]

CD coughed up some electrons that declared:

BTDT...

Two options that work well IME:

1) Fischer frame fixings, specifically this type (other lengths available):

drill the hole exactly as Fischer specify with an HSS drill, NOT a masonry drill. My tip here is to now smear the plastic bit with Araldite and to insert the whole fixing flush into the wall. Smear screw with light oil (to prevent Araldite from sticking) and do up. You may need to countersink the plaster to allow the fixing to go flush.

When cured, take out screw and hang cupboards. As long as you don't exceed about 15-20mm between the screw head and the plastic sleeve, these hold very well due to the extra teeth. The Araldite is really only to stop the sleeve spinning in the hole grinding it out, which is a problem I observed.

2) Buy some 6mm or 8mm stud and some Fischer Vinylester resin mortar

it's more fiddly to set up (you need to hold the cupboard bracket in place while the resin sets) it is *very* strong, even in crappy walls.

You'll have to trim the stud to length, or insert to the required depth - I would recommend a nyloc nut or a touch of Loctite on the thread to prevent it walking off over time.

There are some other new fangled fixings for these types of wall but I can't vouch for them. Stay tuned...

After the Araldite is cured, remove

[Tim S]

Tim S coughed up some electrons that declared:

Oops cut'n'paste error VVVV

[Andrew Gabriel]

I found instructions for drilling thermal blocks on one of the manufacturers websites some time ago, and since following that, I've never had any problem.

Most importantly, never use a masonary drill, and never use hammer action. Neither of these is necessary and will wreck the area around the hole.

Use something like an HSS metal drill bit, to ensure you have a very clean cut parallel sided hole, with no damage to the surrounding area. Then rawl plugs, rawl bolts, and similar work fine.

[CD]

That's where I've been going wrong, HSS from now on & no hammer. A bit obvious now when I think about it, you can almost push your finger in these things.

CD

[CD]

Thanks.

[PeterC]

Would a Bosch Multipurpose Drill Bit be ideal for this?

[The Medway Handyman]

It would - and it is.

Also worth mentioning that you need to get the plug deep into the block to get a secure fix. Rawlplug Uno plugs are excellent for soft blocks.