Conservatory Building Question

JemimaPuddleduck24

I was just looking for some advice. We’ve purchased a conservatory and the company are in the process of building it now. We were unsure about the progress and wondered if anyone could advise if it seems right.

They came out last week and dug a trench which they put a layer of concrete in the bottom. They’ve then been out and built one base wall inside the trench along the outside wall, which is the width of a single brick and one block and three bricks high . After the guys finished that they said they were done and the next guy would be out next week to do the concrete base.

We weren’t sure about this, so we have been looking on the internet. The videos and pictures we’ve found suggest there should be 2 walls at this stage which is where the insulation would go in between So we would be missing a secondary wall along the inside edge of the trench.

Is it likely that the concrete base person would be laying the inner skin wall? Or is he going to turn up and say he can’t do his bit?

Also, they’ve smashed in one of the air bricks on the house wall and there’s a big hole underneath it. Would you expect that?

Hope someone can help as we’re a little anxious that all is not going smoothly. Thank you.

http:// i61.photobucket.com/albums/h49/Jenjie78/Public%20random/conservatory004.jpg

aliwali

Hi are you doing it through an overall company? Is there anyone you could call or have you organised each part separately yourself? I'm no expert, but would be interested to know the answer as we have a company starting to build our conservatory soon.

withabix

Picture looks fine to me.

http://i61.photobucket.com/albums/h49/Jenjie78/Public%20random/conservatory004.jpg

There is no reason to have a cavity wall below the floor slab - it would serve no purpose, especially in a conservatory. Your house itself may not have a cavity below the floor if it has a solid floor. Cavities below floor level are only really appropriate for timber joist ground floors.

The 'floor slab' man will remove the topsoil, place sub-base (crushed stone) inside the perimeter wall and compact it. He will then place a slab of insulation material over that and lay a thick polythene damp-proof course which will also cover the hole left from breaking out the air brick (which should not have been left in place) and then the concrete slab is poured.

EDIT: Having zoomed in on your photo, I see they have installed air bricks in the new wall, which would suggest that they are going to install some form of continuity between your existing (broken out) air brick and the new ones. This may be a plastic duct or similar, below the floor slab.

This also suggests to me that your house probably has a timber ground floor, because your DPC looks quite high compare to the surrounding ground.

macka0

Is the frames going right to the floor or are you having dwarf walls ? If your have dwarf walls there should be an internal skin

JemimaPuddleduck24

Thank you for the replies We weren't sure if we were worrying about nothing, but felt its better to ask people who may know before the work is done, than do nothing and have problems later.

aliwali - we're doing it through a company.

withabix - I'm sure we have a concrete floor in the house. am fairly certain its a cavity wall on the house too.
macka0 - We are having dwarf walls on the conservatory.

So with all the above, when the concrete man comes, i should be making sure there is an internal skin before the concrete base is done?

macka0

the internal block/brick wall should be sat on the footing and not the slab

baldelectrician

You may need building regs approval

In Scotland if it's more than 8 sq mtr (external) then you will need it, it differs elsewhere

withabix

macka0 wrote: »

the internal block/brick wall should be sat on the footing and not the slab

As I said before - completely pointless, as the cavity up to the DPC would be backfilled with concrete anyway. Inner skin on the footings is structurally required for a house, because the structural part of a house is the inner skin of the wall, but is not required for a conservatory, because the structural support is provided by the outer skin, as the conservatory structure sits on that.

frogglet

Our conservatory had a brick outer layer and a breeze block inner layer with a gap in between. The windows were fastened to the brick bit and the windowsills rest on the breeze blocks.
Surely if there is only one outer layer of bricks there is nothing for the windowsills to rest on.

macka0

a cavity has to be below 150 mm below the damp...including inside of the cavity...only been timeserved bricklayer for 25 years... if you constructed it without as said above damp/rainwater would penetrate thru the outerleaf and then run down the inside of the outer skin and straight into your floor causing no end of problems

withabix

A good sequence of photos is shown on the following link:

http://www.regencycontracting.co.uk/galleryThumb.asp?category=12

This shows what is considered good practice for conservatory construction as per my posts.

This series of photos should reduce the OP's fears, if they haven't had the floor cast already.