Dealing with Local Building Control for French Doors

weeg

bigpappa said:

weeg said:

bigpappa said:

weeg said:

Owain_Moneysaver said:

bigpappa said:

So a concrete lintel is out of the question?

Not necessarily, but you'd need a calculation to prove it. 

You need a calculation to prove whatever lintel you use. Both steels and precasts have standard load bearing capacities, and both need a min 150mm bearing either side. You can, theoretically, do the calculation yourself. There are standard loads in the design standards (eurocode 1, part1), and you figure out what is sittting on the wall (so, roof? wall above? first floor?).
In a brick internal wall, my go-to is a robeslee concrete lintel. They come in 300mm increments, and it's REALLY unlikely that a type C won't do the job. (there are loads of other manufacturers, but the idea is all the same) BUT building control will have to ok it.
(FWIW, I'm a domestic structural engineer, but I  work in Scotland where the BC regime is totally different and way more onerous)

I have just looked at the price of a robeslee concrete lintel and its about £20 for 1500mm or £25 for 1800mm.

That seems very cheap? I was looked at a Catinic BXD100 which are about x4 the price - but I really don't mind payng the price for the best product because I am sure a branded product once I put in the BC application I assume they would know more about?

They are cheap - that's why they are so widely used. Even a non-branded one should have a declaration of performance with a load capacity.  I can't think of any advantage you would gain by using a steel. Are you absolutely sure the first floor doesn't sit on the wall? If it's just a wall over then the load is pretty minimal (like 30kg). But don't take my word for it, as I've never seen your house.

Yes first floor sits on the wall. Its a terrace, two rooms up, two rooms down. The wall that I am thinking of putting in double doors is supporting the wall above in the first floor.

I just thought steel trying to look at what can take the most load?

All the builder mentioned was its a pre stessed conceret lintel - is it better to go with reinforced?

Pretty much all concrete lintels are prestressed (It's just a different way of reinforcing).  There is little to no point in putting in a bigger/ more loadbearing lintel than you need. "most load" is basically meaningless in this scenario. But you need someone to come a look at your house and make an assessment of what the load actually is. In my (limited, because I don't spend much time in England) experience, in a traditional terrace house the wall between the front and back rooms supports the floor joists for the upstairs. If the wall runs front to back, it may support the landing.

Ganga

I have read this thread and was surprised to read that you need building control permission to add to a central heating system, so if someone wanted to add a radiator in the front porch of their house would they need BC permission?

bigpappa

Ganga said:

I have read this thread and was surprised to read that you need building control permission to add to a central heating system, so if someone wanted to add a radiator in the front porch of their house would they need BC permission?

Same with an electrical point but if you have it done by a competent person from a scheme then they will inform BC online I think.

bigpappa

weeg said:

bigpappa said:

weeg said:

bigpappa said:

weeg said:

Owain_Moneysaver said:

bigpappa said:

So a concrete lintel is out of the question?

Not necessarily, but you'd need a calculation to prove it. 

You need a calculation to prove whatever lintel you use. Both steels and precasts have standard load bearing capacities, and both need a min 150mm bearing either side. You can, theoretically, do the calculation yourself. There are standard loads in the design standards (eurocode 1, part1), and you figure out what is sittting on the wall (so, roof? wall above? first floor?).
In a brick internal wall, my go-to is a robeslee concrete lintel. They come in 300mm increments, and it's REALLY unlikely that a type C won't do the job. (there are loads of other manufacturers, but the idea is all the same) BUT building control will have to ok it.
(FWIW, I'm a domestic structural engineer, but I  work in Scotland where the BC regime is totally different and way more onerous)

I have just looked at the price of a robeslee concrete lintel and its about £20 for 1500mm or £25 for 1800mm.

That seems very cheap? I was looked at a Catinic BXD100 which are about x4 the price - but I really don't mind payng the price for the best product because I am sure a branded product once I put in the BC application I assume they would know more about?

They are cheap - that's why they are so widely used. Even a non-branded one should have a declaration of performance with a load capacity.  I can't think of any advantage you would gain by using a steel. Are you absolutely sure the first floor doesn't sit on the wall? If it's just a wall over then the load is pretty minimal (like 30kg). But don't take my word for it, as I've never seen your house.

Yes first floor sits on the wall. Its a terrace, two rooms up, two rooms down. The wall that I am thinking of putting in double doors is supporting the wall above in the first floor.

I just thought steel trying to look at what can take the most load?

All the builder mentioned was its a pre stessed conceret lintel - is it better to go with reinforced?

Pretty much all concrete lintels are prestressed (It's just a different way of reinforcing).  There is little to no point in putting in a bigger/ more loadbearing lintel than you need. "most load" is basically meaningless in this scenario. But you need someone to come a look at your house and make an assessment of what the load actually is. In my (limited, because I don't spend much time in England) experience, in a traditional terrace house the wall between the front and back rooms supports the floor joists for the upstairs. If the wall runs front to back, it may support the landing.

The internal wall in question runs parallel to the house front wall and back wall. So I assume it supports the floor joists in the first floor.

I called up two builders merchants and they said these concrete lintels are fine for this type of application and they sell lots. I asked for Robeslee but they didnt have that but said their Type C would do the job - just asked for lebgth and said make sure its put in width way up I think he mentioned.