Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

Having read googlegroups and various FAQs, I came to an interesting
diversion:

Does anyone in the UK sell these:

http://www.constructionfixings.com/p...esiconITSL.htm

?

Seems like a decent answer to fixing large weights to friable block where
leaving a stud sticking out is not desired.

I'm putting up some shelves at the moment and will probably go with the
the drop of Araldite on the wallplug approach - but for something with more
loading (eg LCD TV) I'm not convinced. The resin sleeves in the URL look a
lot more convincing.

Cheers,

Tim

In article ,
Tim S writes:
Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

I read on one of the manufacturer's websites recently how to drill
and plug these walls. The idea is to get a very clean parallel
sided cylindrical hole for a regular wall plug. Use a HSS or similar
drill bit without any hammer action, and not a masonary bit.
I used this recently to mount quite a heavy air con internal unit,
and it felt rock-solid.

For very lightweight loads, you can screw into the blockwork directly
with a woodscrew, without any plug or pilot hole.

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
Tim S writes:
Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

I read on one of the manufacturer's websites recently how to drill
and plug these walls. The idea is to get a very clean parallel
sided cylindrical hole for a regular wall plug. Use a HSS or similar
drill bit without any hammer action, and not a masonary bit.
I used this recently to mount quite a heavy air con internal unit,
and it felt rock-solid.

For very lightweight loads, you can screw into the blockwork directly
with a woodscrew, without any plug or pilot hole.

Ive never had problem using a non hammer type drill and a well fitted
plug and a LONG screw.

If you feel paranoid, get some car body filler and coat the plug with the..

Andrew Gabriel wrote:
In article ,
Tim S writes:
Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

I read on one of the manufacturer's websites recently how to drill
and plug these walls. The idea is to get a very clean parallel
sided cylindrical hole for a regular wall plug. Use a HSS or similar
drill bit without any hammer action, and not a masonary bit.
I used this recently to mount quite a heavy air con internal unit,
and it felt rock-solid.

I agree. No fancy fixing changes the fact that you have a Thermalite
wall (which I've always found an excellent material to fix to).

For very lightweight loads, you can screw into the blockwork directly
with a woodscrew, without any plug or pilot hole.

Not sure I'd trust that though

Thanks to all for the ideas - Jewson have some Fischer plugs that look
suitable - and as mentioned, a bit of body filler/glue will do no harm.

Just noticed on Fischer's website:

http://tinyurl.com/stm5c

in full...

http://www.fischer.de/befestigung/de/poc/index.aspx?page=details&sprache=EN&kat=F5011&ekat= $EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-HK-$INPG-CHEMIE&path=F5011

Which is what I'm looking for for the TV. I'll ask in the local builder's
merchants - most of them keep Fischer products.

Cheers

Tim

Tim S wrote:

http://www.fischer.de/befestigung/de/poc/index.aspx?page=details&sprache=EN&kat=F5011&ekat= $EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-HK-$INPG-CHEMIE&path=F5011

Those are for dense concrete or stone. I thought you were looking for
fixings for lightweight aerated blocks, which is about as different a
material as you could have.

I've found that the Rawlplug 'Rawlbloc' plugs work well in lightweight
blocks; this is not surprising because that's what they're designed for.

--
Andy

Andy Wade wrote:

Tim S wrote:


http://www.fischer.de/befestigung/de/poc/index.aspx?page=details&sprache=EN&kat=F5011&ekat= $EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-HK-$INPG-CHEMIE&path=F5011

Those are for dense concrete or stone. I thought you were looking for
fixings for lightweight aerated blocks, which is about as different a
material as you could have.

I'd considered switching the resin for one more suitable for friable
substrates - I remember, but can't recall exactly where I saw it, a resin
that was claimed to be good for crumbly material. Switching the (expected)
stud for a sleeve would make no practical difference - that's my thinking
anyway.

I've found that the Rawlplug 'Rawlbloc' plugs work well in lightweight
blocks; this is not surprising because that's what they're designed for.


Worth considering - thanks. I'm not set on resin, it's just I've not been
very convinced of other methods up until now.

Cheers

Tim

Tim S wrote:
Thanks to all for the ideas - Jewson have some Fischer plugs that look
suitable - and as mentioned, a bit of body filler/glue will do no harm.

Just noticed on Fischer's website:

http://tinyurl.com/stm5c

in full...

http://www.fischer.de/befestigung/de/poc/index.aspx?page=details&sprache=EN&kat=F5011&ekat= $EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-HK-$INPG-CHEMIE&path=F5011

Which is what I'm looking for for the TV. I'll ask in the local builder's
merchants - most of them keep Fischer products.

Cheers

Tim

Ah.,. a full size CRT TV?

Use at least 6" screws..I remember actually knocking out a whole brick
when trying to mount a TV shelf..could see daylight through the
wall..filled it up with mortar, pressed the rawlpug in, came back next
day, and put a half brick sliver back on the outside, plastered up
...came back thee day after and painted it and put the shelf up..

Oh these wonderful 'period' properties made with cowdung mortar and
friable brick that everyone thinks are o such high quality..give me a
thermalite block any day..

The Natural Philosopher wrote:

Just noticed on Fischer's website:

http://tinyurl.com/stm5c

in full...


http://www.fischer.de/befestigung/de/poc/index.aspx?page=details&sprache=EN&kat=F5011&ekat= $EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-HK-$INPG-CHEMIE&path=F5011

Which is what I'm looking for for the TV. I'll ask in the local builder's
merchants - most of them keep Fischer products.

Cheers

Tim

Ah.,. a full size CRT TV?

Not CRT but heavy enough that I'm paranoid and you have to add the
additional turning moment of a random sprog trying to hang off it to the
equation in my house ;-

Just for the record, found the above anchor sleeves can be ordered by my
local branch of www.fixings-direct.co.uk

Seems that Fischer VS 150C gunk is suitable for aircrete/thermalite which
they have in stock. I'll give it a try. Gluing the thing to the wall
somehow gives me a warmer feeling...


Use at least 6" screws..I remember actually knocking out a whole brick
when trying to mount a TV shelf..could see daylight through the
wall..filled it up with mortar, pressed the rawlpug in, came back next
day, and put a half brick sliver back on the outside, plastered up
..came back thee day after and painted it and put the shelf up..

Oh these wonderful 'period' properties made with cowdung mortar and
friable brick that everyone thinks are o such high quality..give me a
thermalite block any day..

Oh for the days when I used to complain about drilling holes in diamond hard
bricks - good old 1930's!

But the use of crap awkward building materials seems to have spawned a whole
industry of fixings judging by PlasPlugs' range, so that's good for
someone's economy.

Cheers

Tim

In article , Tim S
writes
The Natural Philosopher wrote:

Just noticed on Fischer's website:

http://tinyurl.com/stm5c

in full...


http://www.fischer.de/befestigung/de...s&sprache=EN&k
at=F5011&ekat=$EKAT-HK-DE&path=$INA-HK-$INKT-HK&path=$INA-HK-$INKT-
HK-$INPG-CHEMIE&path=F5011

Which is what I'm looking for for the TV. I'll ask in the local builder's
merchants - most of them keep Fischer products.

Just for the record, found the above anchor sleeves can be ordered by my
local branch of www.fixings-direct.co.uk

Seems that Fischer VS 150C gunk is suitable for aircrete/thermalite which
they have in stock. I'll give it a try. Gluing the thing to the wall
somehow gives me a warmer feeling...

I'll certainly make a note of that, I see them as a useful alternative to studs
and I don't think you'll be disappointed by Fischer. I just wish mor places
stocked them though. Thought the drawings were bloody awful though,
unless I missed it, no mention of the fixing depth at all, just the min/max
mating depth for the bolt.

But the use of crap awkward building materials seems to have spawned a whole
industry of fixings judging by PlasPlugs' range, so that's good for
someone's economy.
And B&Q own brands, useless.
--
fred
Plusnet - I hope you like vanilla

Tim S wrote:
Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

Having read googlegroups and various FAQs, I came to an interesting
diversion:

Does anyone in the UK sell these:

http://www.constructionfixings.com/p...esiconITSL.htm

?

Seems like a decent answer to fixing large weights to friable block where
leaving a stud sticking out is not desired.

I'm putting up some shelves at the moment and will probably go with the
the drop of Araldite on the wallplug approach - but for something with more
loading (eg LCD TV) I'm not convinced. The resin sleeves in the URL look a
lot more convincing.

Cheers,

Tim
If you are fixing between the'dots' you may find that, if there is a
small contact area on the item you are fixing (I had the problem with an
inch square plate for a concealed fixing 'L' shaped toilet roll holder)
tht the plasterboard collapses - I cut it out and used a piece of wood
to support the fixing.

Malcolm

Malcolm Race wrote:
Tim S wrote:
Hi,

I'm about to embark on fixing various things or various loadings to the
walls of a house where I believe the walls are composed of Thermalite or
similar under the dot 'n' dab plasterboard. Block is grey and a 5mm flat
blade screwdriver can be pushed into it - feels like plaster of paris.

Having read googlegroups and various FAQs, I came to an interesting
diversion:

Does anyone in the UK sell these:

http://www.constructionfixings.com/p...esiconITSL.htm

?

Seems like a decent answer to fixing large weights to friable block where
leaving a stud sticking out is not desired.

I'm putting up some shelves at the moment and will probably go with the
the drop of Araldite on the wallplug approach - but for something with
more
loading (eg LCD TV) I'm not convinced. The resin sleeves in the URL
look a
lot more convincing.

Cheers,

Tim
If you are fixing between the'dots' you may find that, if there is a
small contact area on the item you are fixing (I had the problem with an
inch square plate for a concealed fixing 'L' shaped toilet roll holder)
tht the plasterboard collapses - I cut it out and used a piece of wood
to support the fixing.


Or simply welly some muckite behind the board. Body filler or plaster or
whatever.
Malcolm

The Natural Philosopher wrote:

Malcolm Race wrote:

Tim
If you are fixing between the'dots' you may find that, if there is a
small contact area on the item you are fixing (I had the problem with an
inch square plate for a concealed fixing 'L' shaped toilet roll holder)
tht the plasterboard collapses - I cut it out and used a piece of wood
to support the fixing.


Or simply welly some muckite behind the board. Body filler or plaster or
whatever.
Malcolm

Yep - I learnt that from bitter experience when I stuck some speaker mounts
up in my last flat - nice rectangular dent in the wall on the one that
didn't go over a dab. I was going to inject a load of
builder's "structural" filler - I forget which one, have to google again.

Cheers

Tim

OK - Have just installed shelving - so here's how I did it for the record -
as this method seemed to work well:

Many bits are put together from kind folks' suggestions here, some from my
own research. I'm not taking credit for all of it - rather just presenting
a coherent method that works for me in my little cheese house.


Problem: House is made of Therma****e/aircrete/somesuch blocks behind
plasterboard dot n dabbed on. Blockwork isn't so much friable but rather
some loose powder which someone gobbed in and vaguely shaped into cuboids.
Even by aircrete's standards, these things are *poor*.

1) Get 8x80mm (or bigger if required, bigger is better) Fischer FUR frame
fixings (or similar). These have nice teeth that expand outwards over 3/4
length. Some frame fixings only have a few serrations right near the end
and in our application the screw does get that far due to thickness of
thing being fixed (or get a longer screw).

Worth the money and the special order in this case. I really do not think
many other plugs (certainly none that B&Q, local hardware store or Homebase
had) would have stood a chance, or they would be hanging on the PB mostly.
I wanted good fixings into the main part of the wall as these shelves will
have heavy and expensive things on.

2) As instructed, drill hole with indicated size drill bit - being very
careful not to wobble the drill. Straight in and out or the hole will be
oversized. Do not use a masonary bit, use an HSS bit or the hole will be
oversized.

3) Blow out hole - I used a cheap "can of air" inserting the pipe right into
the back of the hole.

4) Mix some rapid set (15 minute) Araldite. Generous blob round the end of
the fixing and a bit along the sides and a generous smear around the bit
that will be level with the plasterboard.

5) Insert plug(s) to full depth. Remove screw if used to get purchase on
plug. Wipe off excess glue.

6) Smear oil on screw - cotton wool stick works well. Only need a light
smear.

7) Do up screw - power driver or drill works best with this Fischer part -
but if using a hand driver, keep pressure on as the supplied screw has a
very shallow thread and can strip the plug whilst it is "fighting" the plug
by expanding it. Finish by hand - with the oil on, the screw comes to a
very definate stop when done - over tightening a lot may strip the thread
cut in the plastic. In fact, even with the thread stripped, these things
still hold, but mental confidence drops...

8) Over next 10 minutes back of each screw a bit and re tighten - just to
break the bond of any glue that got on a bit of the screw that the oil
didn't. In practise I had no problems...

Job done. I don't think those shelves are going to fall off any time soon.

The purpose of the glue to to stop the plug turning if the screw is removed
(my shelves are coming straight off again for room painting, then back up).
If the plug turns a bit it tends to lose its grip in the block as the
powder disintegrates further.

I did try the first 4 screws dry as intended by Fischer (none of the
glue/oil malarky). 3 actually held quite well but the 4th gave way and I
was able to remove the plug with my fingers! Probably a combination of a
slightly misdrilled hole and over tightening. That's when I decided to take
the glue tip on board...

Cheers

Tim

PS - ******** to this in the future when I hang a telly on 4 screws close
together with a significant turning moment - I am now definitely going to
use resin anchor sleeves and bolts.

The message
from Tim S contains these words:

4) Mix some rapid set (15 minute) Araldite. Generous blob round the end of
the fixing and a bit along the sides and a generous smear around the bit
that will be level with the plasterboard.

I wash the holes out with a water pistol and use polyurethane foaming glue.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:

The message
from Tim S contains these words:

4) Mix some rapid set (15 minute) Araldite. Generous blob round the end
of the fixing and a bit along the sides and a generous smear around the
bit that will be level with the plasterboard.

I wash the holes out with a water pistol and use polyurethane foaming
glue.


That's interesting - what particular glue do you use? Enerbond was one that
came up on google but the applicator is a bit industrial! Presumably you
inject the glue into the hole? That would work better - with my method the
glue tends to scrape off leaving less in the hole and most on the wall.

Cheers

Tim