Timber framing questions.

[skipdiver]

Hi folks.

Spent the last year or more renovating my house and am now about to build a conservatory on the back, using single skin timber framing for the walls instead of the usual brick/cavity/block route. This will make the build quicker, give me more footprint and i won't need to get a bricky on site, which is good because funds are now running very low.

My questions concern how to approach the timber framing. My house is pebble dashed unfortunately and this will be painted to make it look half decent, which leaves me with the decision of what finish i want for the conservatory. I quite fancy some form of timber cladding but that presents a problem because one of the walls is within a metre of the boundary, so has to have "reasonable fire resistance" according to the powers that be.

Now as we know, conservatories do not come under building regs if certain criteria are met. One of those criteria is that the walls have to be a minimum of 50% glass. This rule is overridden in a boundary situation, where "reasonable fire resistance" is preferable to the need to keep to the 50% glass rule. With this in mind, i am going to build a full height wall on this side of the conny and am looking for suggestions as to what materials i can use to meet the fire resistance required.

I have been looking at composite cladding such as Marley Cedral for the 2 sides of the conny that are seen, but it seems a waste of money to put it on the boundary side, which is up against a fence and out of view. I've considered some kind of board that could be rendered and painted, but again, that means paying other trades for work i'd rather do myself because at the moment i am time rich and cash poor.

The inside of the wall can be done with firecheck plasterboard, but i am open to suggestions as to what material i can use on the outside for a rainscreen that is fire resistant and not too expensive, bearing in mind that looks are not that important. Maybe something that can be painted to match the house.

Any other hints or tips on single skin timber framing would be appreciated as well.

Thanks

Steve.

 

[MMUK]

Bear in mind that building regs does indeed apply to conservatories, your statement is wrong. I don't know where you got that info from but it is woefully out of date. In any case you will still need a brick layer on site to build a wall up to damp course level and provide either a concrete slab within or a suspended timber floor. Both of these methods of flooring have to comply with building regs.

 

[skipdiver]

Regs do not apply if certain criteria are met, which is what i said in my post. As long as the roof is 70% translucent, the walls are 50% glass and the conservatory is isolated from the main property by external quality windows and doors, then it is exempt. In my time as a joiner/ builder, i have erected scores of them.

The base is already in place, up to damp and ready to go.

 

[skipdiver]

Forgot to mention that it is less than 30 square metres, is single story, will comply with the glazing and electrical regs and the heating will be isolated form the rest of the house.

I'm pretty sure that makes it exempt unless anyone knows different.

 

[MMUK]

Regs do not apply if certain criteria are met, which is what i said in my post. As long as the roof is 70% translucent, the walls are 50% glass

Those restrictions no longer apply as of August 2012.

You state "regs do not apply if certain criteria are met". This is untrue. ANY construction work has to be in compliance with building regs whether or not it is notifiable to the authroities.

Trust me, I'm a property developer :wink:

 

[skipdiver]

Thank you, i didn't know that. I bought this place in October 2012 and have spent most of the time since then either renovating it or doing the odd joinery job. Not done any building work for a couple of years, so i am obviously out of the loop then. I think i will have to do some checking, as i have already come out of the ground.

 

[morfa]

This might be handy:

http://www.planningportal.gov.uk/permis ... ervatories

That link refers to the changes but actually sounds that what you're planning is about right.

 

[skipdiver]

file:///C:/Users/%60/Downloads/004-Are-You-Considering-A-New-Conservatoryv2%20(4).pdf

This is on my local council website and seems to confirm what i thought. I don't need regs if i meet all the exemption criteria, which i will. :?

 

[MMUK]

file:///C:/Users/%60/Downloads/004-Are-You-Considering-A-New-Conservatoryv2%20(4).pdf

This is on my local council website and seems to confirm what i thought. I don't need regs if i meet all the exemption criteria, which i will. :?

I think you may have misunderstood what I was saying.

On a terraced house you can project up to 3m (or 4m if a semi or detached) and up to 50% of the volume of the ORIGINAL (any existing extensions will reduce the max volume) house without planning permission. For a conservatory that meets this particular stipulation, you don't need to register the work with the Council Building Control. However, any work carried out should still be done to comply with any regulations in place.

For instance, you will still need to dig a trench for concrete footings, you will still need to use Class B engineering bricks up to damp course level, your concrete pad (if you are using a solid slab) should be at least 100mm thick and laid on top of 100mm polystyrene with a DPM underneath on a blind of soft sand.

If you are only bricking up to damp, your footings should be at least 400mm deep in clay soil or 600mm in sandy soil. In this case, you don't have to brick a cavity - I lay my DPM in and then the 100mm polystyrene with a perimeter of polystyrene (50mm or 100mm) so you are in effect creating a filled cavity.

 

[skipdiver]

But that's not building regs. That's just good practice which i have done/will do on the rest of the build. I rang my bricky mate who did the oversite and he confirmed that i don't need regs and i know he did the work to a good standard because i helped him do it. The 3 mt and 4mt rule is planning, not regs.

Anyhoo, has anyone got any ideas on the easiest ways to clad the timber frame to achieve adequate fire resistance?

 

[RobinBHM]

Building regs for conservatories: the 50% framework and 75% roof as a description of a conservatory was dropped in the current regs introduced in Oct 2010. Confusingly some boroughs kept the ruling others didnt.

As a manufacturer of orangeries I always email the relevant borough with a sketch and a statement saying: 'this proposed orangery/conservatory is under 30m sq, substantially glazed and is thermally separated from the house, do you consider this to be an exempt structure?' -if they say yes, which they usually, do then I dont apply for building regs.

However, an exempt conservatory will still need to comply with part B, which refers to short fire resistance duration if closer than 1 metre. This may include the need for fire proof glazing, but I cant remember. As Mmuk says, you need brickwork up to damp any way, so maybe concrete blocks or similar would be the cheapest?

You would need to check part B to see what level of fire resistance the cladding needs to be

A structural opening into the house, and part P still need building regs application.

 

[LJT]

If the conservatory meets the exemption criteria only part n Safety glazing and part p electrical safety apply. Part b will not apply however logic would suggest providing fire resistance to a wall on a boundary to protect your own property if nothing else!

 

[MMUK]

If the conservatory meets the exemption criteria only part n Safety glazing and part p electrical safety apply. Part b will not apply however logic would suggest providing fire resistance to a wall on a boundary to protect your own property if nothing else!

Whether the regs apply or not, all work still has to be up to spec. It does not mean you can cut corners.

 

[skipdiver]

If the conservatory meets the exemption criteria only part n Safety glazing and part p electrical safety apply. Part b will not apply however logic would suggest providing fire resistance to a wall on a boundary to protect your own property if nothing else!

That was my understanding LJT. The windows, doors and electrics will all meet the standard required and the fire resistance is something i will do regardless. Someone has suggested using Magnesium Silicate boards to clad the timber framing. It is fireproof, waterproof, strong and stable i've been informed.

Anyone used it?

 

[skipdiver]

If the conservatory meets the exemption criteria only part n Safety glazing and part p electrical safety apply. Part b will not apply however logic would suggest providing fire resistance to a wall on a boundary to protect your own property if nothing else!

Whether the regs apply or not, all work still has to be up to spec. It does not mean you can cut corners.

What specs are we talking about? It either has to be reg compliant or not. No corners will be cut but if i did make a bodge of it, no-one will be coming to check the work out as far as i am aware.

I have built hundreds of conservatories for my mates UPVC company and never seen a building inspector unless the conservatory needed regs for some reason. Usually because an opening into the house had been formed or it was a tiled roof sunroom requiring steelwork to support the roof.

I really don't know what you are referring to as i can find nothing about rule changes in August 2012. I haven't done a building project for a couple of years so may have missed something but as far as i am aware, the rules for conservatories are the same as the last time i built one a couple of years ago.

 

[chippy1970]

You might want to look into this stuff

http://www.vivalda.co.uk/building-boards/cp-boards.html

I'm working on some new flats and we got a firm in to add a steel framed (metsec) penthouse to the existing roof. We are then cladding the walls with cp boards and then hook on insulated render panels go over that.

Maybe something there will suit your extension.

Sent from my Hudl HT7S3 using Tapatalk

 

[LJT]

Steve

Being exempt there is no 'spec' to comply with. As Building Control are not involved the work will not be checked or approved. The householder is responsible for any works carried out. The only protection provided to any future purchaser of a property is that any works should be declared when the property is sold. This gives any purchaser the ability to see what work has been through building control and any work which may have been exempt or carried out illegally without an application if one was indeed required. Hope that makes sense!

 

[skipdiver]

You might want to look into this stuff

http://www.vivalda.co.uk/building-boards/cp-boards.html

I'm working on some new flats and we got a firm in to add a steel framed (metsec) penthouse to the existing roof. We are then cladding the walls with cp boards and then hook on insulated render panels go over that.

Maybe something there will suit your extension.

Sent from my Hudl HT7S3 using Tapatalk

Thanks, i'll check it out.

 

[skipdiver]

Steve

Being exempt there is no 'spec' to comply with. As Building Control are not involved the work will not be checked or approved. The householder is responsible for any works carried out. The only protection provided to any future purchaser of a property is that any works should be declared when the property is sold. This gives any purchaser the ability to see what work has been through building control and any work which may have been exempt or carried out illegally without an application if one was indeed required. Hope that makes sense!

Yeah, that's pretty much what i thought. The conservatory is exempt and it will be built with best practice in mind. All the elements that need to be to regs, will be, namely the glazing and electrics.

As i say, i have built many conservatories for a mates company but never done one with timber framed walls as opposed to brick and block. Most of them didn't need regs and all of them are still standing.