Building on sand

[Ivor Windybottom]

Since Grenfell Building Control have now got 10 years from completion to issue an enforcement notice, and to prosecute the builder. Used to be one year and 2 for the builder.

Are you sure? I've looked for guides but keep finding pages where the author seems to have muddled/blurred PP and BC together into one confusing mess.

Edit: Yes, it's 10 years...

Failure to comply with the building regulations - Building Regulations - Planning Portal

Details of your responsibilities in regard to building regulations

www.planningportal.co.uk

No idea how/whether this applies retrospectively, e.g. to something that was built 9 years ago today.

 

[^woody^]

No wonder you're worried.

I am the Teflon Don

 

[^woody^]

No idea how/whether this applies retrospectively, e.g. to something that was built 9 years ago today.

It's a bit of an oversimplification but in almost all cases, laws are not applied retrospectively. There's a premise that laws "look forward, not backward".

 

[stuart45]

It's only 10 years for works that were completed after the new laws were brought in. Ones that were built 9 years ago from today can't be served with an enforcement notice. Building Control can go to the High Court if needed, in which case there is no time limit. You would be talking about a really serious issue for this. They aren't going to court for someone who has put in a single glazed window without regs.

 

[Ivor Windybottom]

Part of my design that I'll be submitting to planning shortly. Just a rough draft. It's a generously wide/long single garage. The car shown is a BMW X5, which is a huge lump of a thing...

This shows about 1.1m depth from ground level.

I've shown the footings as 450mm. Should this be 600mm for a cavity wall?

I've shown the floor as 150mm with rebar mesh. I'm thinking the edges would be perched on the footings, I'll amend it to show the compacted rock extending down at the edges to meet the top of the footing. I was thinking/hoping that the floor would be hopefully strong enough to span the gap if the soil beneath it shrinks away in future.

Can Celotex/Kingspan be used under a garage floor? I don't need insulation, just thinking as a means of getting up out of a hole.

The internal wall is light buff coloured bricks. Have just seen that it needs an extra course at the bottom in place of the grey block. The internal floor is one course below the outside DPM, I think this is normal for a garage?

All feedback welcomed, don't be polite (wouldn't expect that here anyway!).

 

[Deluks]

Can Celotex/Kingspan be used under a garage floor?

Yes, but don't overdo it!

Cars crushed at Crayford flats after water pipe bursts

Cars are crushed after a burst water pipe floods an underground car park.

www.bbc.co.uk

 

[^woody^]

Part of my design that I'll be submitting to planning shortly

Planners don't need to know about sections or details, just what it looks like and how it appears in context of the surrounding area, and list the materials and colours.

BTW, you don't need to insulate or even build cavity walls to the same standard as a for a habitable room.

 

[freddiemercurystwin]

Can Celotex/Kingspan be used under a garage floor? I don't need insulation, just thinking as a means of getting up out of a hole.

You can use Jablite Fillmaster of a suitable density if all you want is to fill a void, though it does act as insulation, assuming you can buy it in small quantities.

 

[Ivor Windybottom]

BTW, you don't need to insulate or even build cavity walls to the same standard as a for a habitable room.

I know, just overdoing it! I don't see the harm, hopefully it will be drier inside and give a bit of temperature stability during hot/cold weather. It's in a space between our home and the boundary, I already have about 1m path either side so there's no benefit in making it narrower. It's definitely not wide enough for a double garage, hence the extra-wide garage with cavities.

The section was really more for my mind, just wanted to work out how the trusses would look etc. I'm matching the bungalow's roof height and pitch, so they'll match. I'll send the drawing in with the rest. I've also done plans (with/without roof), all elevations etc.

 

[^woody^]

I know, just overdoing it! I don't see the harm, hopefully it will be drier inside and give a bit of temperature stability during hot/cold weather.

It's a waste of time insulating, or even highly insulating a wall and not floors and ceilings. Further, there is absolutely no benefit by insulating an unheated space - it does not make it warmer, nor does it create an even temperature environment. There is a difference in performance between quilt and board insulation and what type of heat they insulate

Part insulating can actually create problems by moving dew points to other surfaces and allowing condensation rather than preventing.

Wide cavity walls are not ideal structurally.

 

[Ivor Windybottom]

We had a single-skin garage at our last house. No DPC either. That was rubbish, everything in there went rusty, cardboard boxes went soft.

I'm sure a modern 9" wall garage will be better than a single-skin, but I like the idea of a cavity to give proper damp-proofing. Three sides will face an open field and the prevailing wind so it will get very wet at times.

The walls and floor will be insulated. I may add a ceilling later. The door will be an insulated one. It won't ever be heated. I'm hoping it will reduce the speed of the spikes and troughs of temperature through the days and nights.

It will probably be mostly used for plastic boats and stored stuff.

 

[metalgarageltd]

I'm planning a garage, which will need planning permission. This is new territory for me.

We have sandy topsoil, on top of sand - it's like a bright yellow beach when you get about 1m down. We've been down to 3m before while doing the sewage system, we only encountered the odd lump of clay among it, but we didn't reach a point at which it became solid clay. We also had several trench wall collapses, it should have been propped really.

It's very clean, nothing brown or black, it looks like sharp sand but with a bit of clay-like stickiness. You could squeeze it into a ball, but it would crumble fairly easily.

It will be single storey, cavity wall with a pitched tiled roof.

The main building is a bungalow with a strip foundation. It seems to be OK, I'd be happy with this for a single storey. But I'm worried that with modern standards they may start demanding piling or a raft foundation. Which seems a bit much for a garage.

Questions...

Will the granting of planning permission automatically lead to building control being involved?
What would building control normally require of this sort of situation?

Thanks all.

Honestly, clean sand is often preferable to heavy clay from a foundation perspective. The main issue is usually trench stability and collapses during excavation rather than the actual bearing capacity.

If the existing bungalow has been sitting on strip foundations for 70 years without significant movement, that’s usually a pretty good indication the ground is capable of supporting a single-storey garage without anything extreme like piling.

For a detached garage, Building Control would normally mainly be interested in:

• foundation depth/type,
• drainage,
• proximity to boundaries,
• structural stability,
• fire regulations depending on size and distance from boundaries.

Planning permission and Building Control are technically separate processes, although the departments do communicate with each other.

Personally I’d be surprised if they pushed for piling on a normal domestic single-storey garage unless there was something unusual found in a soil report. A reinforced raft slab or conventional strip foundations would probably be far more likely.

 

[kingandy2nd]

My plot is on sand dunes with a couple of foot of soil on top.

I piled my garage. Yes it cost more; but it’s less likely to fall down.

I suppose it’s whether your willing to risk all the expense of the above ground materials and labour for the build on a potentially unsuitable foundation.