Steel lintel to window seal problem

E

eire1977

Registered User
Messages
44
Folks,
I need ye're help.
Here's my problem. Currently in the process of building a timber frame house and a part of the front has stone. I got special T shaped steel lintels designed for timber frames which were put in to carry the stone over the 3 windows in that section.
The problem is that there is a 20mm gap between the lintel and the window - (I can put my fingers in up as far as my knuckles).

My plasterer says that the gap is too big to be filled with cement plaster. He also said that the steel lintel won't hold the plaster - which is fair enough.
My engineer suggested that I use steel mesh (covering the exposed lintel and the gap) and hilti nail gun it to the lintel and then it all could be plastered - solving the problem. I tried this but the nails didn't hold. (the stone is very hard and the steel nails bent when it made contact with the stone - also, the power of the hilti gun started to cause the mortar to come away from between the lintel and the stone above). So I'm back to square 1.

I know I should rely on my engineer but to be honest - he doesn’t give a crap, so I'm going to try and sort it by a different avenue.

Does anyone have any suggestions? Anything?
 
Re: HELP! Steel lintel to window seal problem

Expansion foam. If it's PVC window - Celuplast ltd. in Baldoyle ind. estate has a decent choise of PVC mould strips. Silicone will do the job. (Superglue helps to get started).

If you still want to sand/cement -1. use shorter hilti nails, 2. use the new type "threaded" nails for steel, 3. use metal washers (or galvaband) to have a secure mesh fix.
 
Re: HELP! Steel lintel to window seal problem

Have you any way of wrapping the steel mesh around the lintel. Allow it to get a hold at the top of the lintel and wrap underneath?
If the hilti won#t work you can drill small pilot holes in the lintel and using galvanised, washered steel fixings you can screw the mesh in place.
The mesh is necessary to hold the cement render, as it will not bond to steel, as your plasterer says.
The expandable foam can be used to fill the gap , allow it to cure and trim back to allow you to do your finishing work to the exterior an interior.
 
Re: HELP! Steel lintel to window seal problem

Thanks for your replies.
I did mention expandable foam to my engineer and he said it would not be a good job. ..... someone else told me about fire proof expandable foam (non-porous) ... anyone used this? (think it's pink in colour)

Yes, screwing the mesh in place seem like a option. Would self tapping screws for steel be needed?
 
Re: HELP! Steel lintel to window seal problem

It looks like you're reaping the rewards of not having an architect on the job and/or not having working drawings and/or not having someone co-ordinate and regularly inspect the work.

Stick to what you're good at - employ a professional and no, I don't ONLY mean an engineer - in general engineers don't do weathering and construction details, just structures.

ONQ
 
Re: HELP! Steel lintel to window seal problem

I used a hilti gun when plastering around my steel lintel when building to hold on the steel mesh and it worked fine. I believe i purchased " black bullets" on my builders advice and was quite amazed with the power in one of those gun's they are pretty lethal.
 
Re: HELP! Steel lintel to window seal problem


Why would you be doing this on your builder's advice? Should he not be doing this?
 
Re: HELP! Steel lintel to window seal problem


Sorry, can't say I agree with that. The vast majority of drawings produced - even by architects - are devoid of this level of detail.

And, in the absence of engineering, an architect can't produce a drawing for anything - otherwise it's just a 'pretty picture'.

OP - back to your query. I presume your wall is TF/cavity/block/stone, and that the lintel gap is forward of the TF ? I'd be interested in knowing where your window and DPC head is, relative to that.

Anyhoo - you could cut put on a strip of cementitious board - by screw or by nail gun (no ferrous screws, though........they'll rust), and render over that.
 
Re: HELP! Steel lintel to window seal problem

We had the same problem with steel lintels at the front of our house. We have large corner windows and pressed steel lintels (like you describe had to be used).

We ended up with a 15 to 20mm gap over these lintels as the support plates at the corners prevented the windows from being fitted any tighter to the lintel. We flatted corner beads and inserted them into the gap and held them in place with expanding foam (engineer and plasterer discussed this on site and came up with this solution). Has worked perfectly.

If you have PVC windows you should be able to get a filler strip that can be inserted into the gap before plastering (our's are not PVC)
 
Re: HELP! Steel lintel to window seal problem

I know the it sounds more like a job for a builder, but The Window Master might be able to help. He has been in the business for over 20 years and boy does he know his stuff. You could explain your situation. He is based in Dublin. Log onto thewindowmaster.ie for more details. He can fix any repair! His name is Brendan by the way.
 
Re: HELP! Steel lintel to window seal problem

Hi Lucy31, welcome to AAM. In accordance with the posting guidelines, could you confirm whether you have any association with the above company other than being a satisfied customer?
Leo
 
Re: HELP! Steel lintel to window seal problem

ONQ - thanks for your help!

Galwaytt - your cement board might work. What is the minimum thickness this can be got in? (and can it be got from local builder providers?) The reason I ask is that there is not much room to play with, between the lintel and the window opening. What type of screw should I use? And should the lintel be pre drilled before screwing? (sorry of all the questions)

RMDT - can you explain corner beads for me? The windows are PVC.

If I could fill the gap and be guaranteed that it is sealed, I'd paint the lintel - without having to plaster. Is this an option??
 
Re: HELP! Steel lintel to window seal problem


Eire1997, you're welcome for what little it was.

galwaytt, I agree that working drawings are seldom done on houses anymore and its left up to the builder, but threshold and lintol details are precisely what working drawings should include.

Even the overall 1:20 section should show a reasonable level of worked out detail at Heads, Cills and Thresholds, while the Working Drawing Details should show these at a larger scale and specify the type and thickness of each material, their relative positions, and suggest how they go together.

I also agree that engineers information must be included at this level of detailing, but its not the job of the engineer to produce weathering details that take account of his structure. This normally falls to the architect or the architectural technician. The installation of the lintol, the window plus the weathering should be co-ordinated by this detail.

Normally the ope dimensions are given, together with a lintol soffit level and everyone works around them including the window installer, but in this case he was probably expecting some kind of forgiving piece, say a patent render on expamet, to cover the joint.

This comes back to my original comment and suggests there may have been little or no co-ordination and in the absence of an architect, this usually falls to the builder to sort out. It is he who has to stand over all the built work, not just the structure.

ONQ
 
Re: HELP! Steel lintel to window seal problem

ONQ - I agree completely, but at the moment, it's less information on such stuff being generated, not more, that seems to be the norm.
No offence to self-builders - I'm one myself - but all too often, people are just handing out PP drawings to 'builders' and they or the likes of me (supplier to builders, boht self- and otherwise), gets called in to 'fix' stuff.

Mind you, arch fees are not helping the situation. People are trying to save where they can.
 
Yup, that's true, and with a good builder they'd be sound enough, but the cowboys fleece them time and time again...

Mebbee I should produce a book of standard details for house builders or something.

Still with all the previous Part L amendments and more yet to come it'd be out of date on the day of publication.

 
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