Building a front Porch - Please offer a newbie some guidance

[steadyonbob]

Hello Everyone,

I have planning permission to build a porch of 2mtr x 2.5mtr onto the front of my Bungalow. The existing house will retain its external door and there will be no heating in the porch, or perhaps a separate small controllable heater maybe.

Anyway, I really want to have a crack at doing this myself and have built garden walls before, which were quite reasonable and I am a competent DIY'er..

The outside will be rendered when completed by a renderer.

It will have double glazed window openings on both side walls and a front door.

It will be built from blocks, not brick.

The ground for footings is firm about 60 cm down.

i) Do you think I should build it using twin skin walls or will a single skin wall suffice?

ii) Can anyone shed any advice on what types of block to buy for the walls and for below the dpc level?

iii) I plan to dig down about 90cm and then pouring a strip foundation of about 200mm deep and 450 mm wide. Does this sound ok?

Can anyone offer any more advice or tips to help point me in the right direction?

Many thanks,

Bobby

 

[garyo]

I'm currently doing something similar, but around twice the size and subject to building regs (which I guess you're not...)

I'd recommend filling the trench with readymix, unless you really fancy laying that many blocks down in a trench - it's a horrible job. A 450mm wide trench won't even take that many cubic metres. Look for one of the newer type readymix companies that mix on the lorry on demand. I paid £90 per m3.

I'd go for a cavity wall to avoid the cold and condensation problems you'll get with single skin.

Gary

 

[ajrobb]

Have you spoken to your local Building Control? They will advise you on footings. I strongly suspect the porch will be covered by building regs.

I suggest you allow adequate ventilation to prevent condensation. If you fit modern double glazed doors and windows in the porch, you run the risk of trapping moisture from the warm house. Trickle vents over the windows perhaps.

 

[garyo]

My feeling is that you won't need to build to Regs on a porch as long as it's below 30m2 in area and 'wholly or partly glazed'

Gary

 

[marshman]

Do the render walls with cinder blocks or concrete blocks, its won't blow off them like it will thermal blocks.

 

[noseall]

i) Do you think I should build it using twin skin walls or will a single skin wall suffice?

Twin skin.

ii) Can anyone shed any advice on what types of block to buy for the walls and for below the dpc level?

Use 7n dense concrete block below ground but show class b engineering bricks above ground and up to dpc.
Above dpc use 3.5n medium density blocks (not aerated lightweight blocks)as these are ideal for receiving render finishes, i.e. ash or cinderblock, Fibolite, Hemelite etc.

iii) I plan to dig down about 90cm and then pouring a strip foundation of about 200mm deep and 450 mm wide. Does this sound ok?

Sounds great though we tend to mass fill as it is cheaper and less hassle than bricklaying in trenches.

Can anyone offer any more advice or tips to help point me in the right direction?

Get the roof looking right, i.e. proportional and fitting with the main building. This is often the one part of a porch that can look so wrong.

 

[steadyonbob]

Many thanks for all your replies. They are very helpful.

Had a quick chat with Building Control and they say it isn't subject to regs provided I keep an external door on the existing house entrance.

Yeee Haaa!!! I sound like a cowboy. No I'm not a cowboy builder

By the way, I had no idea that there were so many different block types available.

I used to think there were basically just two. One for below ground and one above!

Does anyone have a link to a site with a bit more information about block types and their uses? I am interested to know etc..

Kind regards,

Bobby