Walls
Walls Support the Roof and other Loads-Part K
The fundamental structure of a house is formed by its external walls, which must support the roof and take any other load that is built above. The section of the National Building Regulations that deals with walls is SANS 10400-K and it has several parts, each dealing with building walls, and the elements of how both internal and external walls should be correctly constructed.
Changes to the Legislation
Like much of SANS 10400, Part K: Walls has changed quite substantially, both in terms of the legislation and the section that deals with The application of the National Building Regulations, which is the document prepared by the SABS and published separately to the legislation.
(NOTE: Previously SABS 0400, which became SANS 10400, was published by the SABS in its entirety, with the legislation and a Code of Practice which took the form of “deemed-to-satisfy requirements”. When the legislation changed on May 30, 2008, this was gazetted. The SABS then progressively updated its guidelines and published them over a period of years, as a series of individual documents. These are available from offices of the SABS and from the Bureau’s webstore, HERE. The new version of Part K was published on 29-03-2011 and it costs R517.56 including VAT.)
This article deals primarily with the changes to the legislation, and how it applies to building walls, rather than the South African National Standards.
Structural Strength and Stability of Building Walls
Part K 1 of the regulations states that, “Any wall shall be designed and constructed to safely sustain any actions which can reasonably be expected to occur and in such a manner that any local damage (including cracking) or deformation do not compromise the opening and closing of doors and windows or the weather tightness of the wall and in the case of any structural wall, be capable of safely transferring such actions to the foundations supporting such wall.”
This has been substantially expanded. Previously the legislation simply said the walls should be capable of safely sustaining any loads to which they would be likely to be subjected. It also said that structural walls should be capable of safely transferring such loads to the foundation supporting a structural wall.
There are various walling materials available, made primarily from clay and cement-based products. You will need to decide which is the best material for your particular purposes. Walls can also be built with stone or timber, but each material has its own set of methods to satisfy the requirements.
Solid brick walls normally consist of two brick skins that are joined together and strengthened with brickforce or brick reinforcing and/or wall-ties (a mild steel wire laid between some of the courses to add strength). The interior and exterior surfaces are normally plastered but may be fairfaced (facebrick). Concrete block walls are a more economic option and are often used for garages and outbuildings.
Water Penetration of Walls
Whatever materials you choose to use when you build, the method used for building walls must comply with Part K 2 of the regulations. Primarily they must be built to prevent water penetrating into any part of the building. All cavity walls must be well drained by means of weep holes above a damp-proof course. All cement bricks and blocks are relatively porous and should be plastered or rendered on both sides for thorough waterproofing.
Basements and semi-basements are also referred to in the “new” legislation, and any room below ground must be adequately waterproofed.
The legislation reads: “Where a building includes a basement or semi-basement, the local authority may, if it considers that conditions on the site on which the building is to be erected necessitate integrated designs for the penetration of water into such basement or semi-basement applicable to all construction elements or components thereof, require the submission of such designs for approval. Construction shall be in accordance with the requirements of the approved design.”
In recent years, a variety of alternative construction methods have been developed, most notably in the sphere of cheaper housing. These include the building of walls with insulated fibrecement panels; with fibreglass panels; creating the basic structure with shuttered no-fines concrete; using polystyrene sprayed onto a basic framework; or piling up sausage-shaped bags of sand and cement. If you want to use any altrernative method it would be best to contact your local authority planning division, or building inspector, for guidance.
Roof Fixing
Part K 3 deals with the way in which the roof of any building is attached to the wall and states that this must be done securely and safely and must be able to withstand any natural forces such as high winds or rain and hail. Specifically, it states:
“Where any roof truss, rafter or beam is supported by any wall, provision shall be made to fix such truss, rafter or beam to such wall in a secure manner that will ensure than any actions to which the roof may normally be subjected will be transmitted to such wall.”
While this clause of the legislation is basically the same as it was previously – one word has changed with forces deleted and actions replacing it – there are substantial amendments to the so-called “deemed-to-satisfy requirements” published in SANS 10400, Part K Walls. Similarly there are many changes – more so in the form of additions – to SANS 10400, Part L Roofs.
The Ways Walls Behave in Fire
Part K 4 deals with Behaviour in Fire, and state simple that, “Any wall shall have combustibility and fire resistance characteristics appropriate to the location and use of such wall”.
Brick, block and stone walls are generally accepted as fire resistant. Timber frame with timber or fibrecement cladding need to be certified, and you should check with the supplier regarding these rules for their type of walling, before you decide which material you are going to use for building walls.
Deemed-to-Satisfy Requirements
Part K 5 of the legislation states that Parts K 1 to K 4 will have been deemed to be satisfied “where the structural strength and stability of any wall, the prevention of water penetration into or through such wall, the fixing of any roof to such wall, and the behavior in a fire of such wall” complies with the relevant part of SANS 10400. This standard, “Establishes deemed-to-satisfy solutions for rain penetration and damp-proofing and contains simple design and construction provisions for masonry walls in single-storey and double-storey buildings and framed buildings that do not exceed four storeys; masonry balustrade walls and masonry free-standing boundary, garden and retaining walls.”
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Roofs-Part L
i need sabs for retaining walls. I am doing a project on them and i can’t get it. PLEASE
Good day Penny
I am a new proud home owner and I have a few questions that I know you will assist me with.
My neighbour has gone and ereceted a wall on an existing boundry wall without my consent or even consulting me about it.They have not reinforced it with any wire.It is now higher than 1.8 m.It looks very untidy because they did not even plaster the wall.My questions is :-
1- Do they need a plan to have erected this wall?
2-Are they obliged to have plastered the wall?
3-Do I have the right to break the wall down ( the piece that they have now built)?
4-How/where can I found out as to who the wall belongs to?
Hi I just want to now how far from n broundary can I build a garage and do u need the permission from neighbours.
Hi.
I am extending my driveway gate and I will need to break down the boundary wall pillar on one side of the gate so as to allow for this extension. My boundary wall is 2 brick course thick (220mm) x 2m high with pillars of 440x330mm on each side of the gate. When I rebuild the pillar I will need to throw a foundation for the extra thickness of boundary wall at this point (220mm x 330mm), i.e. the pillar.
My question is – what should the dimensions of the foundation be for the new pillar (220x330mm)? The pillar is not load bearing, just the gate-end of a boundary wall.
Hi Mark,
Firstly was your house registered with the NHBRC? And secondly is the builder registered with them? Both of these have to be done by law. If both of these are true the you have to follow the procedure set down by the NHBRC and claim from the builder first in writing. Then after a set time you can claim from the NHBRC. You have 5 years for major structural defects, and if the dampproofing was not put in under the floor and walls, then that might be considered a stuctural defect. The full procedure is explained on their website here: nhbrc.org/consumer-info/
Your “single brick wall” (the correct term is half brick wall) can be that high so long as it is not a load bearing wall and is only a room division.
Dear Penny,
Please can you advise on the following:-
– Do I have any legal claim against a builder for damp rising in my
house?
– what is the maximum legal height of walls internally allowed is one
brick wide?
my ceilings are over 4 M high with single break walling.
My house is 2 years old. please can you advise?
rgds,
Mark
Hi Ernst,
You don’t say how high the walls are but I am guessing that if it is up to the lapa roof then it must be about 2m high. The regulations allow a wall up to 2.2m high without supporting pillars (piers), BUT the wall must be 220mm-290mm thick. With a single brick (correct term is a half brick) wall 90mm thick then you can go to 0,8m without piers and up to 1.7m with piers (490mm X 290mm) at 1,6m centers. These figures are extracted out of quite long tables that are too long to repeat here. You might be OK if the wall is anchored to the lapa uprights with steel rods as you mentioned. If you are concerned then get a “competent person” (engineer or architect) to have a look.
Hi, I have bought a home with a lapa extended from the back of the house. There has been a single brick wall build by the previous owner on a foundation around the lapa strengthened with brickforce and waterlayer applied. The lapa roof rests on its own legs and is not in contact with the single brick wall as there is a space between the wall and the lapa roof structure. Must the brick wall not be double or can one get away with a single wall built like that. The wall seems to be steady. Two small sliding windows on top of the wall and a sliding door has been installed in 2 sides of the wall. The two outer corners of the wall away from the house was joined correctly and the corners bordering the house seems to be joined with rods. Please advise.
Shaun there are standards – and there is good building practice. Not regulations as such. There are some leaflets that you can download FREE from our sister website Owner Building – here’s the link. I have also emailed you a copy of the C&CI publication, CONCRETE basics for building that covers the subject well.
Good day team.
I would like to find out if there are any standards governing plastering that should be adhered to by a contractor when building new structures. More specifically are there regulations for depth of the plaster to cover brick, and also mixing ratios of the content.
Thanks
Mark, the regulations you need to refer to are SANS 10400: Part K Walls. The table you have referred to is in the old regs (SABS 0400 1990 – which you can download free on this site) and I am not sure whether it has changed. Probably not, although they might have added to it. BUT – retaining walls MUST have plans. And you are absolutely correct in terms of the need for piers. As far as the agricultural drain is concerned, that needs to be constructed BEFORE the wall is built. Have you investigated what foundations have been constructed? Seems to me they are getting it back up as quickly as possible. This may not be sinister – but it also probably isn’t legal. What I find strange is that from the photograph, the earth that is being retained does not appear to have shifted. You need to talk to an engineer, but it seems to me that the foundation trenches and the foundations were probably not adequate in the first place. This all points back to a need for plans drawn by a competent person.
Good day,
I am an insurance assessor dealing with a retaining wall that collapsed, allegedly due to a plumbing trench being left open near the wall and subsequent rain water washing away the foundations. We did not see the wall in its collapsed state, but looking at the wall as it has been rebuilt, it seems to me that it has not been built according to regulations that I have found, which seem to give a maximum height for a retaining wall of 1, 4 m. Is this correct? The wall in question is at least 1,8m high in places, and there are no piers.
We did get some photos of the wall in its collapsed state, which also doesn’t show any piers. We also did not see the alleged trench in their photos. It was also higher than 1,4m. There are no weepholes in the wall, but it looks as if they are waterproofing the back and intending to put in an agricultural drain at the bottom, which I believe is acceptable, but not mentioned in the regs.
Any comment you can give, particularly with the collapsed wall in photos 4 & 5, will be appreciated.
Hi Dino,
If you go to your Local Authority with the address and erf number you should be able to see a copy of the plans and check if any alterations or additions have been approved. If you go to our sister site Owner Building there is a plan and an article on boundary distances and some guidance on Boundary walls and fences.
How close to a neighbours boundary wall can a neighbour build a garage? Does this require planning permission and if so where can one ascertain whether this has in fact been approved?
All land is formally surveyed and boundary pegs are inserted at each point of the boundary (i.e. four points if the plot – erf – is square or rectangular.) Once people build they often removed the boundary pegs. You can get a diagram of your area from the Surveyor General’s office in Pretoria that will show where the pegs should be. If there is doubt as to the boundary, and there are no pegs, you may need to employ a surveyor to re-survey the plot and insert new pegs according to the Surveyor General’s diagram.
What would be the boundary of my property?
By-laws generally regulate the distance between boundary walls and the road – or any other land owned by the council/municipality. There is no one rule or regulation. Generally though this would be the boundary of your property.
How far from the road must the boundary wall be?
Since you posted this query twice, I have responded to it HERE.
Dear Penny
Good Day
I need some clarity and assistance in resolving an issue with regard to the property I recently bought from Cosmpolitan Projects. I recently went to show the house to an architect friend of mine who pointed out structural defaults that I was not aware of. (Skew walls and windows) . He alluded to the fact that the Inspector should not have approved the building until Cosmopolitan broke down the wall to rectify the mistake and re-built it. I also consulted a builder in the area who also concurred that the kitchen wall must be broken down to fix the mistake. In this case I called the bank (FNB) and informed them of the problem and they referred me to the Chief Building Inspector at the City of Tshwane. What
I want to know and need assistance with-is whether as a home owner I am within my rights to demand that Cosmopolitan Projects breakdown the wall anf fix it before I occupy the house or what other remedies are available to me to resolve this matter. Your urgent response will be appreciated!
You can probably use a non-combustible cladding. I am surprised the building inspector didn’t make any suggestions. What I would do is to approach the local authority and ask them to give you acceptable options.
Good afternoon
I bought a house 10 years ago in Stillbay. It is a thatched roof house and on applying for approval to have the roof changed to an “aluzink”roof the building inspector found that the wall between my house and garage is not a firewall. (It was bought that way and apparantly it was changed from a seperate single garage to an attached double garage.) As the wall seperating the house and garage is a normal external double wall,how do I change it to a firewall?
Thanks
John the magic height is 1.8 m – which links to “minor building works” & here too (scroll down to the end). See if the links I have provided here help you, otherwise get back to me. I will in the meantime try and get something onto the website regarding walls in general – because there are also building standards relating the the NBR – supporting pillars, brick force and so on – that must still be adhered to, even if the wall is lower.