Battling building regs over limecrete, damp and radon

[stables]

Hi , I'm converting a grade 2 listed stable block and have come up against a building regs issue.
I intend to use limecrete flooring as the building has no DPC but find we are in an area that requires us to provide basic protection from radon. The risk of radon is stated as being 5% or less but the council is insisting we need to use a radon barrier unless we can provide a credible alternative solution. Any ideas??
We contacted bre and had suggested installing a radon sump with an extraction fan under limecrete without a radon barrier but no one is willing to put this down on paper to appease building control...has anyone else heard of this method being sucessfully deployed? Is it possible to test for radon in an unsealed and unoccupied building with clay floors? as I'm willing to bet that our 95% odds of not having a radon problem will be bourne out thus solving that particular issue

Furthermore just to add to things the BCO has stated that " Also as a result of not providing a Damp Proof Membrane there would be no protection against damp penetration from the ground." even though the conservation officer has talked them through the theory of how limecrete works in old buildings. It's just not a concept that fits within their guidelines.

The stables have several internal tudor brick and lime mortar partitions with no DPC so even if we put a radon barrier in it would be almost impossible to seal it against these walls so would in my view be a complete waste of time and detrimental to the fabric of the building as it would push any ground moisture into the walls. What the council want us to do is to put in a dpc and tank all the walls to 1m above floor level and put in a concrete foundation...it's exasparating!

All suggestions welcome

 

[MatthewC]

Hi Stables, welcome. The tradition on here is that for your first post you get asked for PHOTOS, lots of PHOTOS, please! Then you get asked if you like Kit Kat?

I can't help about radon - it didn't seem to be an issue with my extension to a Grade II listed house in a conservation area (see my blog at the blue spot on the right). However, I laid a limecrete floor and had a lovely BCO who was interested in what I wanted to do, listened to my explanations and happpily signed it off. If you do it on notice then they have to send someone and you can have an on-site discussion looking at the job in progress; if you send plans then they can argue for ages and you can't really start.

As I understood it in 2011, for a listed property they had no option to over-rule the planning department, but I think that rule might be about to change. Do you already have planning permission?

Matthew

 

[stables]

Hi Matthew,
thanks for your reply. photos attached of outside - more to come of internals. and yes i like kit kats.

the previous owners had been granted planning permission but this was for a conventional concrete floor with DPC. we're seeking amendments. we've got a friendly and positive Conservation Officer but the BCO is very young and sticking to the letter of the regs.

Stables

 

[MdB]

There are three sets of permissions you need to get: Planning, Building Control and Listed Building Consent. I guess you have already found this out and have discovered that they sometimes don't agree as to what is best for the building. Make sure you don't end up in the middle and get them to sort conflicts out between themselves.

You are changing the use of the building from a stable to a home which will change the requirement as to what is considered acceptable damp. In our house a DPM is a must. A breathable floor just wouldn't be able to cope with moisture. This does mean there is a bit of damp in the old walls but these are only 20% of the building and we have brought it down to acceptable levels through lowering the outside ground levels and other measures.

In your case, this bit intrigued me:

unsealed and unoccupied building with clay floors?

I am very much not an expert on this but I would imagine a good clay floor would act as a DPM anyway? Thinking about it, I'm not sure it would - maybe somebody else here can comment.

 

[stables]

internal photos
showing ground level excavated to stone footings, some walls cement rendered which run with water when the weather's poor

 

[stables]

MdB

unoccupied and with unsealed clay floors - i referred to this as, as i understand it, this means we can't run a normal radon test as this requires a sealed building.

we are struggling with the change of use of the building as the BCOs are suggesting the building must comply to the same standards as a new build and these don't necesarrily sit well with the conservation of the building

 

[Zebra]

The stables have several internal tudor brick and lime mortar partitions with no DPC so even if we put a radon barrier in it would be almost impossible to seal it against these walls so would in my view be a complete waste of time and detrimental to the fabric of the building as it would push any ground moisture into the walls. What the council want us to do is to put in a dpc and tank all the walls to 1m above floor level and put in a concrete foundation...it's exasparating!

Sounds exasperating! However, just suppose you were to put in a damp proof course, as well as the damp proof membrane/radon barrier. You wouldn't then need tanking as well. I have put in a damp proof course in my 17th? Century brick walls, and now live in a dry house, with a new concrete floor with insulation and damp proof membrane, there is no moisture being pushed into the walls, and not really any detriment to the character of the building I feel, though there are others who may argue for more traditional methods. Furthermore the insertion of a damp proof course is arduous, disruptive, and probably to be undertaken only after other methods of damp management have proven ineffective. When you say the council want a concrete foundation - do you mean underpinning the existing walls? Does it need that? You can insert a damp proof course and damp proof membrane without underpinning, so is that evidence of a separate problem?

 

[LadyArowana]

For a smidgin less than 50 of our lovely British Pounds you can have these people send you detectors which they then analyse some time later and it will give the radon reading. Without doing that the risk is calculated just based on the surrounding geology and may be inaccurate at the particular property level. Not sure that you would want to wait for as long as the test takes ( 4m altogether, 3 for exposure and up to one for test results ) and being unoccupied / undergoing building work is one of the things they mention as influencing results..... but it might be worth the wait.

http://www.ukradon.org/article.php?key=measureradon

 

[MdB]

In Cornwall, all new building has to have a radon sump fitted (we had to fit one in our new extension) - not that it does much by itself. It is there such that a fan can be fitted in the future if high radon levels are detected. There is no requirement to have a radon test though...

 

[Penners]

Stables - whereabouts are you? If Building Control has demanded that you make provision against radon, is this because your property has been tested or is it just that you are in a high radon area?

If th elater, it might be worth your while spending £50 on a detector to check out the property. See Lady Arowana's post above. When we lived in Oxfordshire we ran into this problem, so we installed a test device from the Environment Agency (as it was then). It took about 4 weeks and the analysis showed our house to be well below the radon "action level".

If your test shows this to be the case you can show the results to your BCO. If it shows that you're above the action level, then you should be taking precautions anyway, for your own health's sake.

 

[MdB]

In Cornwall you still have to have a radon barrier and sump even if you have a negative test. At least that is my understanding for unlisted buildings. I don't know if this is different for listed.

 

[robgil]

Are radon barriers water proof?

Edit - please disregard that as the silly question of the century.

 

[Keith Bowman]

Are radon barriers water proof?

Edit - please disregard that as the silly question of the century.

I'm sure Doug could make you one from lead which would be both radiation and water proof

 

[Penners]

Are radon barriers water proof?

Edit - please disregard that as the silly question of the century.

Doesn't seem like a silly question to me, Rob.

I'm no expert on this, but I know you can buy plastic sheeting that doubles as a radon barrier and damp-proof membrane. So it seems the answer is yes.

 

[DJH]

Are radon barriers water proof?

Edit - please disregard that as the silly question of the century.

I'm sure Doug could make you one from lead which would be both radiation and water proof

Nice one Keith. I've done plenty of dampcourse work in lead along with large weatherings and safety trays under baths and showers where they have been above decorative ceilings below, along with liners for fountains and the biggest lead,or weathering slate ever, I'm sure! It was for the new M&S in Manchester and the pipe being weathered was just under 6 feet in diameter.

Can't remember laying a lead DPM/radon barrier though............ did some shields for an x-ray room once....... memories

Doug

 

[Penners]

A radon barrier doesn't have to be a radiation shield. It simply has to be impermeable to gas - in this case radon. So a properly specified plastic membrane will do the job (as I understand it).

 

[MatthewC]

There are three sets of permissions you need to get: Planning, Building Control and Listed Building Consent. I guess you have already found this out and have discovered that they sometimes don't agree as to what is best for the building. Make sure you don't end up in the middle and get them to sort conflicts out between themselves.

In the area where I live, Planning does both PP and LBC (so one application generates two) but BC is totally separate so that's a completely different application. They don't even seem to talk to each other, so there was no direct conflict. I'm sure that the BCO was not interested in exactly what the PP/LBC or drawings said as he was just far too busy; as far as I was concerned this was the benefit of doing it by notice.

I can't find anything written, but I think the BCO's view on radon was that our limecrete kitchen floor was much better in this regard than what was there before so it was a good thing!

 

[stables]

Hi all, i've submitted a few responses but they don't seem to appear (I'd assumed as I'm new they need to pass the editors).
Thanks for all the replies, I'll try to get back into the conversation.
Also posted photos but no luck on those either, will try again.
Stables

 

[PeterI]

Hi all, i've submitted a few responses but they don't seem to appear (I'd assumed as I'm new they need to pass the editors).
Thanks for all the replies, I'll try to get back into the conversation.
Also posted photos but no luck on those either, will try again.
Stables

If you nip back to the previous page, you'll find they've appeared now.

 

[Penners]

It's great to see your photos, Stables. What a wonderful building! What part of the country are you in?