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
All solid masonry or stone walls require plans. When it comes to precast (vibrecrete) walls, I think that most local authorities have standard requirements in terms of both manufacture and erection. Check with your local authority.
Who erected the palisade fencing? Do you know? If neither of you did, then you could dispute removal and insist that he builds the new wall adjacent to the palisade. i.e. Say you don’t want the palisade facing removed. If neither of you own it, and you agree to its removal, then insist that any money made from the sale is split 50:50.Perhaps you could check with your local authority whom they say “was” the fence. Some municipalities state that walls and fences are owned jointly by neighbors.
In terms of foundations for his wall. He has absolutely NO right to build anything on your property. Make sure that you accurately plot the boundary and don’t allow any building to be done on your side. And finally, your neighbour cannot go ahead and replace the fence with a wall without your written consent PLUS the approval of the local authority.
Hi Steffan,
Part K of the NBR specifies the regulations as they apply to walls of all types. The important elements are whether the wall is structural or non-structural; and if structural, whether it is load-bearing. The relevant SANS specify things like foundations (and footings) as well as the compressive strength of the mortar that should be used, as well as wall dimensions. While the SABS has standards that relate to stone retaining walls, I cannot find anything that relates specifically to stone and mortar walls, so assume that the general masonry wall specs apply. In any case you will need plans to build a wall from stone and mortar; and a “competent person” (who is qualified in construction) will need to submit these for you. Such a person should have the knowledge to advise you.
Hi Martin. It isn’t clear what the wall is for, but there will definitely be height restrictions. There will probably also be restrictions in terms of building another wall right next to the current boundary wall. I suggest you contact your local authority for guidance.
Darren you cannot build a wall without plans. You can though put up a precast wall if you wish. The manufacturers will be able to advise minimum and maximum heights.
When you say “interlocking bricks” do you mean bonding? Bricks essentially “interlock” when they bond. i.e. Each one should overlap the next by half. If the bricks are not correctly bonded, then the structure could collapse. My book on Owner Building describes the process well. In fact any book on brickwork will describe the process, and probably have photographs. Or you can do a search on the Internet that shows what it looks like.
The regulations regarding structural masonry can be found in SANS 10164.
I am currently having a house built through a developer (plot and plan, free-standing, own titled). I would like to know what the regulations are when interlocking bricks from internal wall to exterior wall? The interior wall being built was initially in the incorrect place, after shifting it, there are much less interlocking bricks now. The builder is insisting that they have done the necessary, but it has now been plastered and I cant check it. What are the regulations regarding this?
Hi,
What is the maximum height, in Kwazulu Natal, that I would be-able to build a wall on the boundary of my premises, with out the need of having plans approved? I currently have a hedge.
Regards,
Darran
Good morning-could you kindly advice me with regards the building of a wall right next to the current boundary wall. Are there ay height restrictions applicable. Apparently the height restriction for the boundary wall are 2,1m. I live in Nelspruit, South Africa
Good Day
I would just like to know what regulations apply to stone masonry walls and where I can read the applicable regulations. Some of the things I would like to know include, for example, what restrictions apply to the height which you are allowed to build with traditional stone and mortar or with slipform stone masonry and what dimensions are applicable to stone masonry load-bearing walls, footings etc.
Thank you in advance
Good Day,
Can you please advise on the requirements, especially with the municipality, to replace a palisade fence in front of your home with a solid build wall (and what about when replacing with a precast wall)? What is the requirements to replace and extend an existing boundary wall? Our neighbour wants to replace and extend this wall, but with a style,colour and brick totally different from the present facebrick, and which are also not complimentary to the facebrick of our house. With that he also want to extent the wall and remove the palisade inbetween and claim that the palisade are then his to sell(which we have resently painted). He also seems to want to not dusturb his paving coming right to the fence at present and requisted that we remove our beddings for the foundation and wall to be then in our yard, thus moving the boundary and decrease our yard. No measurements had been done.
Hi
I live in a complex. Next to the complex is an open field and construction is underway to build a block of flats there. A road has been build running next to my complex boundary wall. The road however, has been built higher than the level of our ground and any pedestrians walking on the road can see into our yards over the boundary wall and we can see them. I would like to know if this is allowed and if not, how can I take action?
Many Thanks
All cavity walls must be built in accordance with the National Building Regulations. Wall ties must be installed in an evenly distributed pattern (uniformly staggered) and at the specified rate, depending on the face area of the wall and the width of the cavity. According to the NBRs the wall ties must comply with all requirements contained in SANS 28. This national standard covers the dimensional and material requirements of metal ties suitable for walls having cavity widths of up to the largest likely to be found in masonry walling constructed to dimensionally co-ordinated sizes. I think that either butterfly ties or modified PWD ties may be used, but not brick force. The fact that builders are using other methods doesn’t make this legal. The NHBRC was established to improve the standard of building in SA (which is known to be bad) … If cavity walls aren’t corrected reinforced, the house could collapse!
Thank you. Very helpfull advice. I’ll just rewind the clock and re-do it as prescribed.
I don’t understand. If you belong to the NHBRC then you need to do things their way!
Yes, this is a late enrollment.
Are you registered with the NHBRC?
Hi, I have constructed a small house in George and have used wide brickforce to tie the two leafs of the cavity wall together in stead of butterfly ties. The NHBRC is now on my case and refuse to enroll the house before the non-compliance has not been rectified. I have used face-bricks on the outside. Is my construction method totally unacceptable warranting rebuilding of the house or can it be accepted if certain corrective measures are done i.e. waterproofing of the outside wall with SIKA.
I have used this method before and have never had any problems and I believe it is being done by many builders.
Not at all Jan. But you will need plans for a garage, regardless of the materials you choose to use. And you are right, it is considerably cheaper than using bricks and mortar.
Hi
I just bought a property and would like to know if there are any regulations that would prevent me from building a double Gerage using Rhino board or Marine-ply for the exterior like this : http://www.instructables.com/id/How-to-build-a-garage-from-the-ground-up/ I know it common in the states and much cheaper than bricks
Hello Jose, I don’t known anything at all about the building industry in Namibia, but it seems to me that there are no national standards as there are in South Africa. The South African building regulations are not intended to be restrictive, but rather to give sensible guidelines. The NHBRC also has guidelines which are useful. A lot of this information is available on our web site. If there is anything specific you want to know, let me know.
Please bear in mind that all building regulations provide MINIMUM specifications. You might consider some specs excessive in the manuals you have come across, and this might well be so in some situations; but in others it is more than likely they are vital. As an a architect, I would assume you are working closely with engineers who would be able to advise you.
I totally agree with you.
I am architec and I have seen some manuals about masonry walls where It is prescribed the use of control joints in an exessive extend, I think, and that is why I want to consult the building regulations in order to know what is advised on this regard
I am architec working for the Namibian Gov. and for all the profesionalls,who practice in the building sector in this country, It is indispensable to know and consult the Building Regulations in force here.
I am an architec from Spain,who is currently working in the MRLGHRD in Namibia, and I need to know this regulations to become familiar with the way and the restrictions,the buildings are design and done in this country.