Conservatory floor insulation building regs

[zaarin_2003]

Hi all,



I wonder if you might know the answer to a question I have.

We are having a replacement conservatory built and wish to move the kitchen from its current position to inside it. The sink will be located on the far side of the conservatory and the waste pipe would run from that to the gully, which is where the existing kitchen is, the other side of a wall on the opposite side of the conservatory.

This means laying a drainage pipe horizontally, at an angle with a drop, through the floor.

The conservatory company have stated that our plumber will not be able to run the waste pipe through the selotex insulation layer of the new floor, because it will be running almost horizontally, at an angle enough to ensure a decent drop for the water to flow, but not steep enough to prevent it cutting a long trough through the insulation, which is what they don’t like. They state that recent changes to building regulations prevent us doing this.

This complicates things for us, because it means the pipe will need to be above or below the selotex, at a more slight angle, and probably require a pump to pump the water along, rather than relying on gravity.

I presume the new regulations being referred to are the ones detailed in Approved Document L: Approved Document L, Conservation of fuel and power, Volume 1: Dwellings (publishing.service.gov.uk) which came into force June 2022. Is this correct? And, if so, I presume the concerns are related to the requirement for continuity of insulation. These requirements specify that insulation must be free from gaps and such and that any services breaking the insulation layer must have insulation tight around it, and presumably not a long channel cutting through it.

My question is, do these new regulations even apply to extensions/conservatories? From what I can see, paragraph 4.17 of Approved Document L, which details the continuity of insulation requirements, only applies to new dwellings. There is also a provision at 4.17(h) which allows for services to run through it anyway. Under 10.12-10.13 (adding a conservatory or porch to an existing dwelling), it mentions that fabric elements such as insulation need to meet the U-value requirements of section 4.7-4.8 and table 4.2, but there is no mention of ‘continuity of insulation’ such as there is for new dwellings.



Thanks

Z

 

[^woody^]

You can't put a kitchen or sink in a conservatory, as if you do it becomes an extension and requires full building regulations for everything, not just the floor.

 

[zaarin_2003]

You can't put a kitchen or sink in a conservatory, as if you do it becomes an extension and requires full building regulations for everything, not just the floor.

Thanks. Ok,

1. The rest of our conservatory complies with full building regs, so no concerns there. It’s is only the implication of running a pipe through the insulation in the floor we are concerned about, as per the above.

2. Do you know where it says that a conservatory is classed as an extension if a kitchen is in it? (The heating system is on a separate system from the rest of the house)

3. I don’t think it matters in relation to my question anyway, because paragraph 10.7 of Approved Document L, which concerns extensions and not conservatories, also states that any new thermal elements (such as the floor) must comply with paragraph 4.7 in regards the U value and, as with conservatories, continuity of insulation is not referred to as being a requirement, meaning in my view, it is not a requirement for anything other than new dwellings.

In other words, if you assume my conservatory is indeed classed as an extension, you can substitute the words extension for conservatory in my original question and it still stands.

 

[Notch7]

1. The rest of our conservatory complies with full building regs, so no concerns there.

So I presume you have made a building regulations application for you replacement conservatory and are having the building inspector visit??

 

[^woody^]

The rest of our conservatory complies with full building regs,

That's interesting. How have you dealt with fire safety, if there is all that glass (or plastic)?

Building regulations use the normal dictionary definitions of conservatories and extensions and kitchens, and so a conservatory does not have a kitchen in it, nor a sink, else it becomes a utility room.

The answer to your pipe question is an easy one, and I'm surprised your builder can't work it out. Basically, you put the pipe in the floor and you work out if you need to insulate around it.

 

[mrrusty]

This means laying a drainage pipe horizontally, at an angle with a drop, through the floor.

You're mad.

Kitchen sink with a long near-horizontal run? what could possibly go wrong (unless you don't actually do any cooking in your kitchen).

 

[zaarin_2003]

You're mad.

Kitchen sink with a long near-horizontal run? what could possibly go wrong (unless you don't actually do any cooking in your kitchen).

That’s very unhelpful. If you can go through the insulation (which is what I’m asking) and the drop is enough, then what’s the issue?

 

[zaarin_2003]

That's interesting. How have you dealt with fire safety, if there is all that glass (or plastic)?

…

The answer to your pipe question is an easy one, and I'm surprised your builder can't work it out. Basically, you put the pipe in the floor and you work out if you need to insulate around it.

It’s mostly brick, with bifold doors. Personally I’d call it an extension on that basis alone, but ‘conservatory’ is what it said on the tin.

Anyway, it’s not the builder who is having trouble - he wants to run the pipe under the floor at a decent angle for the water to flow down and it would pass through the insulation layer at an angle (ie not vertically through it) across the length of the whole room. It’s building control who have the issue! They say the new regulations say you can’t run services through the insulation layer like that - that they have to pass through with as little impact on the continuity of the insulation as possible. Our pipe would run essentially through the layer of insulation from one side of the room to another, not just through a couple of inches.

 

[^woody^]

They say the new regulations say you can’t run services through the insulation layer like that

If the insulation is thicker than required, then you just channel into it. If not, then you add extra insulation under the pipe to compensate for the insulation you will be cutting out for the pipe.

However, the pipe, the run and the connection should comply with the manufacturer's guidance, Part H and local water bye-laws - which a waste in a floor probably won't comply.
Normally a drain would be put in and then the waste connected to that. Running a waste in the floor is asking for trouble.

 

[mrrusty]

That’s very unhelpful. If you can go through the insulation (which is what I’m asking) and the drop is enough, then what’s the issue?

Kitchen sinks in kitchens where people actually cook get all sorts of rubbish down them - washed off fat, rice, bit's of carrot, porridge, earth off veg, you name it. At some point in time, that lot will gum up the horizontals. We have a short section - about 400mm, and I have to jet it out with the hose in the plughole every so often. Likewise at my mums where she has about 2m of near horizontal. Always getting blocked.

Never heard of fatbergs? with the best will in the world, it is impossible to prevent some fat going down the pipe, and it WILL congeal in horizontal runs. The longer the run, the more likely it will get blocked.

 

[zaarin_2003]

If the insulation is thicker than required, then you just channel into it. If not, then you add extra insulation under the pipe to compensate for the insulation you will be cutting out for the pipe.

However, the pipe, the run and the connection should comply with the manufacturer's guidance, Part H and local water bye-laws - which a waste in a floor probably won't comply.
Normally a drain would be put in and then the waste connected to that. Running a waste in the floor is asking for trouble.

Oh, re the waste, I’m probably not using the right terminology. It’s a pipe from the sink which will carry the water from that down to the gully is it? I’m sure all that is fine.

The only thing the building control guys had an issue with was passing through the insulation layer. But our plumber suggests doing what you’ve suggested; just layering insulation over the top of the pipe as it lowers to cover it.

 

[zaarin_2003]

Kitchen sinks in kitchens where people actually cook get all sorts of rubbish down them - washed off fat, rice, bit's of carrot, porridge, earth off veg, you name it. At some point in time, that lot will gum up the horizontals. We have a short section - about 400mm, and I have to jet it out with the hose in the plughole every so often. Likewise at my mums where she has about 2m of near horizontal. Always getting blocked.

Never heard of fatbergs? with the best will in the world, it is impossible to prevent some fat going down the pipe, and it WILL congeal in horizontal runs. The longer the run, the more likely it will get blocked.

Yes, I do agree. We’d like to avoid all that for all the reasons you mention.

 

[zaarin_2003]

So I presume you have made a building regulations application for you replacement conservatory and are having the building inspector visit??

That’s right.

 

[mrrusty]

Yes, I do agree. We’d like to avoid all that for all the reasons you mention.

What I'm trying to say is don't rely on even a decent fall keeping it clear when there is kitchen waste. The base of the near horizontal pipe gets yucky and sticky and gradually builds up and closes the space. You really want sink waste going straight out in to a gully.

 

[^woody^]

Oh, re the waste, I’m probably not using the right terminology. It’s a pipe from the sink which will carry the water from that down to the gully is it? I’m sure all that is fine.

Normally a drain would be put in and then the waste connected to that. Running a waste in the floor is asking for trouble.