Difference between bonding and dri-wall adhesive?

[Lounge About]

Hello

I'm fitting a cast iron insert to bare brick and have read that you can use bonding to do this.

I have a bag of dri-wall adhesive going to waste and wondered what the difference/problems would be if I used this instead.

Any thoughts on this would be a great help, cheers

 

[NickB_99]

Hello

I'm fitting a cast iron insert to bare brick and have read that you can use bonding to do this.

I have a bag of dri-wall adhesive going to waste and wondered what the difference/problems would be if I used this instead.

Any thoughts on this would be a great help, cheers

starters for 10 -

1) Bonding is an undercoat plaster for applying to brick/block under a skim plaster coat, and dri-wall adhesive is an adhesive for dabbing plaster board onto brick/block walls. They are two different usages usually.

2) I believe that dri-wall adhesive can shrink after setting, whereas Bonding will not.

3) Bonding is pink or sometimes grey in colour with some coarse particles in - dri-wall is white and more smooth in consistency.

A couple of words of caution -

- If your bag of adhesive has been open for a long time (>1wk), then chances are it will go off very quick. Probably too quick.

- Also not sure what your cast-iron is for - if it's related to a fire, gypsum plasters e.g. Bonding, don't like intense heat

 

[noseall]

Dry wall adhesive is also referred to as bonding compound, so is ofen confused with thistle bonding plaster.

As stated above one is a backing plaster ideal for low suction backgrounds and the other sticks plasterboards to walls.

 

[Richard C]

I don’t know who advised you that but Bonding plaster is certainly not suitable, it has low strength & will fail very quickly when exposed to the heat you will get around that cast iron fire insert; gypsum fails very quickly when exposed to temperatures much above 50 degrees. Drywall adhesive is not suitable either. You need to use either a specialist heat proof render or a sand/cement/lime mortar mix. You cannot use conventional plaster on the walls surrounding the insert either as that will also quickly fail due to the heat.

The work you’re doing may also be notifyable, subject to Building Regulations, inspection & certification unless you use a HETAS registered installer. Stove inserts usually have insulation around them to avoid cooking the surrounding brickwork; what sort of cast iron fire insert are you fitting?

 

[Lounge About]

Thanks for the replys

The instructions for fitting the victorian coal fire are from

http://www.victorianfires.co.uk/fitting_a_fireplace/cast_iron_insert_with_marble_mantel.html

It has a seperate concrete fire back

 

[Richard C]

The instructions for fitting the victorian coal fire are from
http://www.victorianfires.co.uk/fitting_a_fireplace/cast_iron_insert_with_marble_mantel.html[/QUOTE]
Manufacturers (or more likely supplier) recommendations or not, using gypsum Bonding plaster to stick the insert in place is not good advice IMO. It does contain Vermiculite which has insulative properties but the Gypsum bonding agent is not suitable to withstand such high temperatures & will crumble & fail; perhaps their view is that it does not matter once it's all in place.

Don’t take my word for it, contact British Gypsum & see what they say; I would also be very interested to hear their opinion.