Failed rendering - recommended approach

[Lons]

.....

Doubt very much that you can be forced to repair or replace any or all of your render with anything more than the existing finish.

....

It's there in black and white in the Regs...I checked !

So reality could be that if you had dodgy render you'd simply let it deteriorate further as it would be so damn expensive to do anyting else.

Which section of the regs? I hadn't noticed it.

I'm not disagreeing with you as I'm sure it's there but I have regular and extensive contact with building control officers and in fact a few years ago when I was a part time lecturer, part of my job was to tutor them in the technical section of plastics in construction. My local inspector was one of my pupils and a friend.

Reason I queried it is because in reality, even when written into the regs, there can be ways around the situation and commonsense can come into play. Most of the inspectors just want to help if approached correctly. They only dig in if you're trying to cut corners.

A typical exemption also which conflicts is when replacing windows where the regs will only allow low emisivity d/g but you don't actually have to use that if it's direct replacement without changing the frame.

I converted a grade 2 listed stable recently which caused very different problems and to meet the planning restrictions for instance the timber sliding windows were compromised and insulation specs were increased elsewhere to compensate.

Your rendering is a repair situation and I stand by my opinion that as such you can replace it. I still very much doubt that however they might wish to, they can't force the issue.

That isn't to say however that it wouldn't be worth doing if you can afford it as the benefits must be there!

The ludicrous situation exists that when extendind a property usually the extension is to very much higher spec than the existing building and they cannot and will not pressure anyone to upgrade that!
You can end up with a utility room with a full glassfibre jacket but the house with no cavity inulation, 50mm in the loft and nowt under the floor - how stupid is that?

 

[RogerS]

It's possible this has been superseded. It's a downloadable PDF but difficult to give the link.

Building Control Guidance Note
Subject
CONSERVATION OF FUEL AND POWER 2006.
Guide 5 – APPROVED DOCUMENT L1B Conservation of fuel and power – Work in existing dwellings.
24
Issued
07/04/06
Rev
Page
1
of
11
From 6th April 2006 there are significant changes to the Building Regulations that cover the Conservation of Fuel and Power in buildings. Energy performance relating to works and extensions in existing buildings is based on a revised elemental approach in which insulation and efficiency thresholds are set for individual parts of the building envelope and services.
There are requirements for standards to be achieved for ‘Thermal Elements’ (walls, floors and roofs), ‘Controlled Fittings’ (windows, doors and similar fittings) and ‘Controlled Services’ (heating, hot water, ventilation systems and lighting). Regulations apply whether as part of an extension, dividing a house into flats, replacing windows, extending a heating system or applying render to a gable wall, or changing a buildings energy status.
Extract of L1. GUIDANCE ON THERMAL ELEMENTS.
Thermal Elements - (Refer to Guide 24 – (2) for further guidance) refers to a wall, floor or roof that separates the heated or cooled space from the outside. Works relating to thermal elements can arise in building an extension, a material change of use, a material alteration, changing a buildings energy status or when carrying out other renovation works. Refer to guide 24 (2).
The requirements for ‘Thermal Elements’ represent a significant change in regulation since it requires efficiency improvements whenever a roof, wall or floor is replaced or renovated. Thus the replacement of render or tile hanging to a wall will require insulation works to be undertaken at the same time. The AD gives guidance on the U values that should be achieved depending on whether an element is newly constructed, rebuilt, retained, replaced or renovated. NOTE: consider carefully the potential for condensation problems and the controls necessary to prevent it when upgrading existing construction).
Renovation of ‘Thermal Elements’: is defined as the provision or replacement of a construction layer, such as external render, tile hanging or internal plaster. It would not include decorations or re-pointing brickwork. Where 25% or more of an elements surface area is to be renovated the whole element should be thermally improved (see AD L1B Table 4 (b) extract below).

Just replacing casement sashes is considered a repair and so outside the regs, I thought. Concurs with your comment.

Listed buildings - the Conservation officer trumps Building Control - so it's difficult to be specific as each building is done on a case-by-case basis.

 

[Lons]

The AD gives guidance on the U values that should be achieved depending on whether an element is newly constructed, rebuilt, retained, replaced or renovated. .[/color]

Just replacing casement sashes is considered a repair and so outside the regs, I thought. Concurs with your comment.

Listed buildings - the Conservation officer trumps Building Control - so it's difficult to be specific as each building is done on a case-by-case basis.

Thanks for that info RodgerS

Interesting! I thought replacing existing was accepted - missed that!

I must admit that these days I read up only the bits I need to for current and future work and as I have increasingly specialised that it becomes less and less.
The regs are changing constantly but certainly your example would be true or even higher spec now. My mate often teels me that much of their time is spent updating their database and knowledge.

You're right about the windows but my example was a large stable in 3 sections built at different times and sort of added ad hoc.
We were allowed to extend and gut the building, replace glass lights with conservation rooflights and create several new windows but the windows we were forced to use by the planners were inferior and did not comply with building regs. - Stupid scenario IMO

We anded up building a fantastic property for my customer and it blends in beautifully in its' setting. But..we had a hell of a ride with the planners who acted like little Hitlers (no offence to any Nazis out there ) and one of them actually told me they would prefer the building had been allowed just to fall down. A beautiful 300 yr old stone structure. Sacrilage IMO :shock:

Still..the satisfaction of creating something like that even though for profit is akin to producing a unique piece of furniture, a turning or a woodcarving (my favourite but sadly neglected pastime)

Bob

 

[softtop]

I'm not sure how old the building is but having done a lot of work on older properties using lime I would definitely recommend it for the breathability, as has been said.

Injection DPMs only harm older buildings by moving the damp elsewhere. Unfortunately you have to accept that the building needs to absorb and release moisture over the year. The more breathable materials you use the better this will work, and the less chance you have of damp patches etc.

In case it's any use SPAB has a free technical advice line where they will talk you through various options - very knowledgeable and friendly:
Technical Advice Line:
Monday, Tuesday, Thursday and Friday
(9.30am - 12.30pm) 020 7456 0916
Wednesday
(9.30am - 12.30pm) 020 7043 1075

Count yourself lucky it's not listed!

Good luck with it.

 

[RogerS]

Hacked off some more render to try and get a feel for the scope. Not quite as bad as I feared as some of the render - although blown away from the underlying bricks - was dry as a bone.

Discovered that the bricks are only there to give a square corner but the scratch coat on the stonework seems pretty sound which is great news.

The semi-bad news is that the corner is moving downwards....there has always been a fine crack and I knew that that corner of the house wasn't sitting on granite.(well, none of it is) ..and, to be honest, over the 300 odd years that parts of the house have been here, a lot of movement/sinkage has taken place. But that goes with the territory of an old property. Certainly not thinking about underpinning at this juncture.

So will let it breath and talk to my plasterer about using lime although I don't know how the junction between lime and cement render works out. He'll know.

We'd probably never have bought it if it was listed!

 

[RogerS]

I'm not sure how old the building is but having done a lot of work on older properties using lime I would definitely recommend it for the breathability, as has been said.

Injection DPMs only harm older buildings by moving the damp elsewhere. Unfortunately you have to accept that the building needs to absorb and release moisture over the year. The more breathable materials you use the better this will work, and the less chance you have of damp patches etc.

In case it's any use SPAB has a free technical advice line where they will talk you through various options - very knowledgeable and friendly:
Technical Advice Line:
Monday, Tuesday, Thursday and Friday
(9.30am - 12.30pm) 020 7456 0916
Wednesday
(9.30am - 12.30pm) 020 7043 1075

Count yourself lucky it's not listed!

Good luck with it.

Softtop, you are a star! I had forgotten about SPAB and they already have a webpage with FAQs

http://www.spab.org.uk/advice/technical ... t-renders/

Thanks

 

[softtop]

Glad it was useful.

 

[Elldot]

AndyT - We have a Victorian house, stone and brick, facing south west, and the back wall had been cement rendered and painted. I now know that's the wrong treatment and we have had it all removed and replaced with proper lime mortar and limewash. Specialist builders are available if you look for them!

I'm Bristol based too and looking to replace our cement render with lime - can I ask what was your experience and who did you use?

Elea

 

[AndyT]

AndyT - We have a Victorian house, stone and brick, facing south west, and the back wall had been cement rendered and painted. I now know that's the wrong treatment and we have had it all removed and replaced with proper lime mortar and limewash. Specialist builders are available if you look for them!

I'm Bristol based too and looking to replace our cement render with lime - can I ask what was your experience and who did you use?

Elea

Well, I'd rather not say at the moment as some problems have arisen so I don't want to mention any names until I've got them sorted out one way or another! Sorry that's not a very helpful answer.