lintols over stone heads?

[karlosmaximos]

im currently working on a job for a customer who wants stone cills and heads to match existing.
do i need to install a normal cavity lintol over the top of the stone head,and then cavity tray,or use a conc lintol on the inside and just put cavity tray in?
being in the trade for 26years you'd think id know by now, but first time ive done it

 

[stuart45]

Normally sit them on top of a catnic or similar. Cast stone isn't load bearing.

 

[karlosmaximos]

i did think of that,but obviously dont want the lintol showing under the stone

 

[r896neo]

Just span the catnic right over the top of it and make sure to use a healthy bead of silicone under the front lip of the catnic to seal between it and the stone head.

The only problem with this is obviously you then have to include a concrete fellow on the inside leaf to span the opening and also you need to insulate and close the reveal that is left under the catnic. But some jablite and then plasterboard dabbed to the head of the reveal will sort it.

 

[stuart45]

You can get re-inforced structural cast stone lintels if you havn't already bought non structural ones.

 

[karlosmaximos]

Thanks guys
i'll put them over the top, and the conc undernesth inside,i normally use cavity closers so insulating/dot n dab isnt a problem

 

[noseall]

Modern day stone headers are a cosmetic item and will need to sit within a proprietary steel lintel as with block or brick masonry.

They are 100mm thick and are single piece up to about 1.2m after which you will have to use a two piece affair with matching pointing for the joint.

 

[r896neo]

I think they look pretty grim on top of a catnic because you see the steel in the reveal. This is especially problematic when you have a mullion jambs and head set which often have a chamfered front edge to the head.

Much nicer to bite the bullet and pay the few quid extra for a concrete boy on the inside and then you get to enjoy a realistic looking stone head without the nasty steel reveal.

 

[noseall]

The visible amount of steel is minimal and hardly nasty, particularly if the steel is coated black.

I can think of far more offensive details to catch the eye, especially with things such as faux Georgian bar windows and painted roofs.

 

[themiddleagedun]

Yes agree... catnic underneath, then DPC tray, then the stone head.
The metal lintel won't be too noticeable.

 

[stuart45]

Non load bearing cast stone lintels are designed to go on top of catnics, and with the catnic lintel on top can fail under self weight.
If you don't want the catnic showing it's better to pay extra for a load bearing one.

 

[noseall]

If you don't want the catnic showing it's better to pay extra for a load bearing one.

True, but who is going to fuss about 20mm or so of lintel showing that can easily be covered with a trim or painted the same colour as the window. It does not make any sense.

 

[r896neo]

In my experience the kind of people who pay the extra for nice stone heads are exactly the kind of people who will moan about steel showing in the reveal.

I find the idea that a decorative stone lintel would fail under its own weight pretty far fetched.

 

[karlosmaximos]

The amount of things ive already changed on this job due to customer changing mind is unbelievable,so would they notice the steel under the lintol?-probably yes.
The windows are going to be wood,so a small trim will hide the steel.
Im gonna put them on top of the lintol
I'll post a few pics when complete.....

 

[stuart45]

I find the idea that a decorative stone lintel would fail under its own weight pretty far fetched.

You might think it's far fetched, but it is a fact, mainly with the longer ones, which could be in 2 pieces as well. You have to remember that as they have been handled a number of times there may be small fractures that are not visible and can crack much later when installed if not supported.
I have had one go when me and the hoddy picked it up.
On most sites you wouldn't get away with putting the catnic over the top.