arched lintel

[cliff1010]

I am a about to put in an arched window but am finding it hard to find the correct lintel. I know you can have one made for you but am concerned re cost. has anyone any ideas on where I can get one the size I need is 186cm across and from the top of the window to where the arch finishes is 86cm. The biggest off the shelf one I have found is 1600cm across.
If I don't find one could I put in a larger straight one ?

Thanks in advance.
Cliff

 

[freddiemercurystwin]

Why would you want to put a straight one in if you want an arched one?

 

[theprinceofdarkness]

Do it the traditional way, wooden former and tapered bricks. It worked on the Maidenhead Viaduct.
Frank

 

[cliff1010]

thanks for the replies, should have explained re the straight one.
The building control want the outside of the annexe we are converting as plain pebble dash. I had not intended to do anything fancy with the bricks around the arch so thought if I was allowed to put in a straight one would that work ? Now it seems I cant get an arch the size I need off the shelf if I use the former and build my own do I need a steel lintel also or just the brick arch?

Cliff

 

[theprinceofdarkness]

You can cast your own lintel. You need to get someone to approve of your rebar size. I have cast colour matched lintels, get the inside of your woodwork really smooth, a couple of coats of emulsion, then give it a coat of wax polish as a release agent. Put in a couple of inches of fine concrete mixed 3:1, well tamped - this is your outside surface, lay in first bar and repeat. A concrete lintel of this size is a heavy weight. It might be better to cast it in-situ. Use thick ply for the front and back, one cut into 12" high sections and make sure that the underneath of the former can withstand the 5-6 hundredweight of wet concrete. Hold rebar in correct location, fill to first 12", screw on next 12 " section (each side to keep weight balanced), carrying on filling and raising the front. And very important that there is no possibility of leaks where it sits on the existing bricks/blocks.
Frank

 

[IJWS15]

If you are pebble dashing anyway follow theprinceofdarkness's advice, former and cut blocks, should not take long.

Use sliding wedges under the former so you can drop it a little without disturbing the blocks when you remove it.

 

[cliff1010]

thanks for the replies, you all sound very knowledgeable now I am thinking about it would I need a lintel either purchased or made in situ if I do the following. Make a former of the window slightly larger and build a brick arch this would do two things get away from the lintel idea and also look nicer than pebble dash as I could bring the bricks out slightly to look better.

Advice if this would work or if I would still need a lintel doing it this way ?
I think this would work as at present we have a square window higher on the wall and a lintel above it, the top of the arch starts about half way down this opening so I don't think the fear of taking the bricks away and re building is an issue. If that makes sense.

Thanks for all the advice.

 

[cliff1010]

Hi just to finish this topic off,
I got in touch with building control and they tell me it needs a lintel designed. I asked a few builders merchants in my area and was given prices but no drawings, going to someone else he looked at it and has now been great getting in touch with building control and it turns out building a former as I first thought and a double header brick course as an arch is ok.
Just waiting for BC to agree.

Cliff