# Forum Home Renovation Plastering  Plastering over steel lintel

## Kaiser Soze

Hi all
I need to finish off a door surround with exposed brick on the vertical sides and a steel lintel on the top. The new door and architrave occupies the outside bricks of the double brick wall. I need to dress the exposed inside skin and the cavity.
Can anyone pass comment on these solutions?
I was thinking of using masonry adhesive to fix dry wall to the exposed brick sides but that means the drywall will be exposed or will be covering up the cavity between the walls. Because of the issue with the drywall being exposed to the cavity damp air/elements etc what is a better solution. 
And...how do I dress the steel lintel.
Am I right that I can simply prime the visible lintel then use adhesive to 'glue' drywall to the lintel. 
How would the pros seal off the cavity before dressing is probably the real question!! - Expanding foam, cement?
Bad drawing attached! 
many thanks...in advance

----------


## SydneyMetro

As you have suggested, you can fill the gap with expander foam and use WR (water resistant) plasterboard with masonry adhesive. 
As for the lintel, you can glue plasterboard on there with liquid nails. Prop up the board from the bottom to give time for liquid nails to dry.

----------


## Kaiser Soze

Thanks SydneyMetro - will the lintel need priming to take the liquid nails or if I need apply plaster?

----------


## Rod Dyson

Hi Kaiser, I have a couple of concerns with this. 
Firstly the using the expanding foam to fill the cavity is a great idea. You will not need to use wet area plasterboard in this application. 
Next I would be concerned about the expansion rate of the steel and masonary being different. Therefore you should not have any joins near the steel lintel. I would use a full sheet over the door and cut the door opening out so the joins are at the sides of the door, horizontal. If you have sufficient masonary above the lintel to fix to and keep the board straight, and you are putting arcs around the door, I would avoid fixing to the steel at all. You can put liquid nails on the back of the arc to hold everything in place. This will allow the steel to expand and contract without effecting the plasterboard. 
Another option, if you need to fix to the steel, is using daubs of silicone about 300mm apart, this will also allow for the movement in the steel.  
If you used liquid nails or plasterboard glue, and join as I have suggested you most likely won't have any problems, it is just better to be on the safe side if you can. However, if you used the liquid nails, or plasterboard adhesive and joined over the door you will get cracking for sure. 
Just on the off chance that you already have plasterboard on the masonary wall above the lintel and you were going to join up to it. I would cut the plasterboard right up to the ceiling or cornice line and replace the entire panel, as a join there is bound to crack. 
Cheers Rod

----------


## SydneyMetro

If the lintel is raw, should be fine. If its painted, then you might need to prime it.

----------


## watson

:Spyme:  
OK there's a few dodgy methods being touted here.......Sydney Metro...it may not be doing your business any good in the members' estimation. 
(IMHO)

----------


## Kaiser Soze

> Hi Kaiser, I have a couple of concerns with this. 
> Firstly the using the expanding foam to fill the cavity is a great idea. You will not need to use wet area plasterboard in this application. 
> Next I would be concerned about the expansion rate of the steel and masonary being different. Therefore you should not have any joins near the steel lintel. I would use a full sheet over the door and cut the door opening out so the joins are at the sides of the door, horizontal. If you have sufficient masonary above the lintel to fix to and keep the board straight, and you are putting arcs around the door, I would avoid fixing to the steel at all. You can put liquid nails on the back of the arc to hold everything in place. This will allow the steel to expand and contract without effecting the plasterboard. 
> Another option, if you need to fix to the steel, is using daubs of silicone about 300mm apart, this will also allow for the movement in the steel.  
> If you used liquid nails or plasterboard glue, and join as I have suggested you most likely won't have any problems, it is just better to be on the safe side if you can. However, if you used the liquid nails, or plasterboard adhesive and joined over the door you will get cracking for sure. 
> Just on the off chance that you already have plasterboard on the masonary wall above the lintel and you were going to join up to it. I would cut the plasterboard right up to the ceiling or cornice line and replace the entire panel, as a join there is bound to crack. 
> Cheers Rod

  Thanks Rod
The lintel has been fitted into the brick wall which is plastered quite thickly. The plaster was chipped away to expose the brick thus forming a slight rebate which the lintel is sitting in. I was hoping to simply render over this area which includs the lintel. 
Maybe I'm overthinking this, can I simply just use harwall plaster over steel?

----------


## Rod Dyson

Yes you can render this but you will need to use expanded metal over the steel. but do not fix it to the steel.  Fix it to the bricks above. 
Cheers Rod

----------

