6m extension thoughts

[Nathan110]

Hello all,

Thoughts on this please

Suspended floor with block and beam. 2 vents only at the front - is this sufficient?

Also a sleeper wall to support the beams mixed with engineering bricks and concrete blocks - thoughts?

Many thanks in advance for your input

 

[sxturbo]

What's BC say?

 

[Nathan110]

Have asked their opinion of course but thought I'd get some input from here too. Any thoughts about mixing concrete blocks with engineering bricks for the sleeper wall & perimeter supporting walls too?

 

[John D v2.0]

Mixing is no problem at all, saves cutting the blocks down.
Air bricks seems a bit light, but as long as the free area is enough, it would be ok.
There isn't any timber there so it should be less critical.

 

[Nathan110]

Thanks John for your very helpful reply.

I'm curious to see what the builders will do about the vents from the existing house - I'm not if you can see it just in the back of the house. There's 4 air brick openings. Would there need to be a channel that feeds into each of the dead spaces unde the blo K and beam. Each area is 2.4x5.7m. Im not an expert of course but one air block vent seems to very light intuitively. Thoughts?

 

[Nathan110]

I've made attached the pic to show it clearer

 

[Nathan110]

The block and beam have been lowered to ensure there is enough space for insulation and screeding etc to make the floor level flush with the existing house. Concrete t beams are 3m hence the need for a sleeper wall to stagger the beams to cover the approx 5.5m span of the house

 

[Nathan110]

The drop from the house to the garden floor level that extension is built on is approx 1m

 

[SpecialK]

I would be putting a door in the side of that so I could use it as storage!

Why have they used air bricks and telescopic vents when its so high above ground level? Will you be having a patio / large step?

The airbricks could also go in the side walls of the extension too...Might make it easier to build the steps...

 

[Nathan110]

I would be putting a door in the side of that so I could use it as storage!

Why have they used air bricks and telescopic vents when its so high above ground level? Will you be having a patio / large step?

The airbricks could also go in the side walls of the extension too...Might make it easier to build the steps...

I was thinking a 3m flat patio from the patio and then central steps.

I would also love to have that void as storage but where would you construct a door and how would it keep the structure stable??

 

[SpecialK]

If you are having bifolds with a drainage channel it might be a good time to think about the airbrick positions.
You could just core cut through the wall and run pipe to the front / side of the new patio if required...

Not sure about access underneath. I would assume a lintel on both courses as you would a normal door opening?

I was thinking a 3m flat patio from the patio and then central steps.

I would also love to have that void as storage but where would you construct a door and how would it keep the structure stable??

 

[Nathan110]

If you are having bifolds with a drainage channel it might be a good time to think about the airbrick positions.
You could just core cut through the wall and run pipe to the front / side of the new patio if required...

Not sure about access underneath. I would assume a lintel on both courses as you would a normal door opening?

I don't think cutting through the concrete blocks at the front would then be sufficient support for the concrete t beams that run across.

The plan is go have 4m bifold at the front. Are you thinking of a pipe that channels air flow from existing house through the side or front of the extension?

 

[SpecialK]

A suitable spec lintel would be fine? I'm not a builder or structural engineer though... Probably only need a 600mm opening to crawl through?

If you are having bifolds at the front with flush access are those airbricks going to be covered? Its not a massive issue as above..you can core cut into the void and run vents further down.
Or have vents in the side walls...

I don't think cutting through the concrete blocks at the front would then be sufficient support for the concrete t beams that run across.

The plan is go have 4m bifold at the front. Are you thinking of a pipe that channels air flow from existing house through the side or front of the extension?

 

[Nathan110]

I'm thinking to do the flush patio also as a suspended floor with a block and beam so it makes sense to think about your suggestion with the storage at the front of the patio for that segment of void (the void under the extension will go to waste I guess - the side will be a flush walkway too) . The vents are going to get covered it seems so will need to ask them to think how they will channel the whole thing from existing through 6m ex + 3m patio.

 

[Nathan110]

This is block and beam spec attached for our project. Any suggestions or would anyone do anything differently.