Decking above basement build?

[RedMango]

Hi all,

 

Currently I'm planning a build to start in April for a deck 6m x 4m that extends out from our bifold doors but currently there is about 5ft drop from the doors.

 

My plan is to dig out 2 or so feet and create a storage area beneath the decking. 

 

I would love a shipping container as it would be perfect size, quick and easy but access is an issue.

 

I'm trying to figure out if building a single skim aerated block basement but struggling to figure out the roof/decking structure.

 

2nd option would be to just have open access and use oak beams on raised steel supports co created in. Would be easier but the storage underneath would be open to the elements so not ideal.

 

Any options or inputs appreciated.

[Nickfromwales]

59 minutes ago, RedMango said:

Hi all,

 

Currently I'm planning a build to start in April for a deck 6m x 4m that extends out from our bifold doors but currently there is about 5ft drop from the doors.

 

My plan is to dig out 2 or so feet and create a storage area beneath the decking. 

 

I would love a shipping container as it would be perfect size, quick and easy but access is an issue.

 

I'm trying to figure out if building a single skim aerated block basement but struggling to figure out the roof/decking structure.

 

2nd option would be to just have open access and use oak beams on raised steel supports co created in. Would be easier but the storage underneath would be open to the elements so not ideal.

 

Any options or inputs appreciated.

DIY it in EPS ICF blocks? You'll have issues with rain penetrating if you just use aerated block, unless you can render externally?

[RedMango]

8 hours ago, Nickfromwales said:

DIY it in EPS ICF blocks? You'll have issues with rain penetrating if you just use aerated block, unless you can render externally?

I would render as I have access and the rest of the house is render but I like the idea of ICF, didn't consider it as I thought it would be costly but this would be great.

 

I'm not sure about the filling with concrete due to access, what's the length of run they can usually pump concrete? The closest a truck can get would be about 20m.

 

Still leaves me with figuring out the roof to decking combo. I would just do a normal flat roof then deck above but I don't like the idea of water not draining off.

[JohnMo]

Think your going to need your structural engineer input. With a 5ft drop your balustrade becomes structural and your decking also. Then you need drawings these need to be approved, then you get building control involved... arms and legs and it grows.

 

I would put this in the difficult basket, and move on. If it isn't on the plan, it isn't approved and BC tell you to knock it down. Job for after completion certificate is issued.

[Nickfromwales]

44 minutes ago, JohnMo said:

Think your going to need your structural engineer input. With a 5ft drop your balustrade becomes structural and your decking also. Then you need drawings these need to be approved, then you get building control involved... arms and legs and it grows.

 

I would put this in the difficult basket, and move on. If it isn't on the plan, it isn't approved and BC tell you to knock it down. Job for after completion certificate is issued.

He's not doing a build, this addition IS "the build"  

[Nickfromwales]

4 hours ago, RedMango said:

I'm not sure about the filling with concrete due to access, what's the length of run they can usually pump concrete? The closest a truck can get would be about 20m.

If you've 2 mixers on site and 3 bodies you can mix and pour for a small DIY job like this. Don't choose librarians, get some guys with thick arms and strong backs, as the pace will be relentless for an hour or two.

 

I guy feeding the next mix into the empty mixer, 2 guys supporting/hand-balling the mix into flexi-tubs and into the ICF. If you're on site to help out even better. Don't attempt this on your own btw..... 

[JohnMo]

3 minutes ago, Nickfromwales said:

He's not doing a build, this addition IS "the build"  

5ft drop still needs a structural engineer input, design and still need to comply with BRs 

 

1 minute ago, Nickfromwales said:

If you've 2 mixers on site and 3 bodies you can mix and pour for a small DIY job like this. Don't choose librarians, get some guys with thick arms and strong backs, as the pace will be relentless for an hour or two.

 

I guy feeding the next mix into the empty mixer, 2 guys supporting/hand-balling the mix into flexi-tubs and into the ICF. If you're on site to help out even better. Don't attempt this on your own btw..... 

We had a section of wall we hand filled used an on demand concrete lorry, he mixed a barrow load at a time, we then back filled the icf with flexible plastic buckets, for zero mess. It isn't quick, and it's hard work.

[Nickfromwales]

3 minutes ago, JohnMo said:

It isn't quick, and it's hard work.

What was the cost of a cube from the dry wagon, if you can recall? Saw one in action in Ilford, was quite impressed by the concept.

[JohnMo]

4 minutes ago, Nickfromwales said:

What was the cost of a cube from the dry wagon, if you can recall? Saw one in action in Ilford, was quite impressed by the concept.

Can't recall, but certainly quite a bit more expensive than ready mix, mostly because the guy stays in site a lot longer. But way less work than cement mixer yourself.

[markc]

1 hour ago, Nickfromwales said:

What was the cost of a cube from the dry wagon, if you can recall? Saw one in action in Ilford, was quite impressed by the concept.

I have just paid £118+vat per Qube from the barrow boys (mix on site truck)  … that’s not the company name, just they always have barrows and will barrow into place for you.

that price was based on 20 - 25 cube

Edited August 7 by markc

[Nickfromwales]

Prob with ICF is you need to pump or hand-ball from a flexi bucket to get it into the 150mm gap. Would require staging to do that from a barrow, successfully I expect.

[RedMango]

I'm all sorted for the calcs and BC etc.

Regards ICF I'd love it but unfortunately as it's just me doing it solo, I don't think I'd have the speed to mix & hand ball it in quick enough to get an even spread before killing over.

 

I think open with oak beams or aerated block & render (or wrap & clad) is my two options all considering.

 

I kinda like the open oak beams, although doesn't really add storage but it keeps good air flow to the air bricks on the house which is a plus. 

Edited August 7 by RedMango