Floors
Building Regulations that Apply to Floors-Part J
The Application of the National Building Regulations that apply to floors (Part J of SANS 10400) are certainly not exhaustive. In fact, if you think of how much of our house is floor, it’s what we might, in South Africa, describe as a biekie min. But the authorities have, at least, increased this part of the document from a single page to nine pages (although these include a page of references to other SANS that need to be taken into account, and more than a page of definitions) plus a cover page, a Foreword, Contents page, an Annex that gives the official, legal Regulations (see below), a one-line Bibliography – on a full page, a couple of blank pages and some info about the SABS Standards Division.
Changes to the Law
Like all the other parts of SANS 10400, Part J, Floors, has two sections. One section covers the Regulations (the National Building Regulations and Building Standards Act, 1977 and all its amendments) and the other covers how they should be applied (previously what fell under the “deemed-to-satisfy” rules).
In terms of the Regulations (the law), there is one substantial change to the first general requirement that previously stated that any floor of a building must simply “be strong enough to safely supports its own weight and any loads to which it is likely to be subjected”. It now states that “any floor of any building shall be designed and constructed to safely support its owns weight and any actions which can reasonably be expected to occur and in such a manner that any local damage (including cracking), deformation or vibration do not compromise the efficient use of the building or the functioning of equipment supported by such a floor”.
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In addition (and this hasn’t changed):
- Floors must be fire resistant and where necessary, non-combustible.
- Floors of laundries, kitchens, shower-rooms, bathrooms and toilets (hooray, they are no longer referred to as WCs!) and urinals must be water resistant.
- Timber floors must have adequate under-floor ventilation.
- Concrete floors supported on ground or filling must be constructed in such a way that moisture will not penetrate the floor slab.
As always, the Regulations state that these requirements will be “deemed to be satisfied” if the design and construction of the floor complies with this part of SANS 10400. However, if the local authority deems it necessary, certain other requirements may be needed. For instance the local authority may demand that the entire area within the foundation walls of any building be covered by a suitable damp-proof membrane, and in the case of a basement, or semi-basement, they may require adequate sub-soil drains to be provided under the floor to drain and therefore remove any water that accumulates.
Interestingly, the Regulations now define the word “adequate” in this context:
a) in the opinion of any local authority
b) in relation to any document issued by the council, in the opinion of the council
So if you’re not sure of anything that relates to floors and flooring, approach your local authority for guidance. They are obliged to help you.
Application of the National Building Regulations
as they Apply to Floors
In addition to a number of SANS that relate to building materials including boards, timber, concrete and fire testing of materials, the SANS states that Parts A (general principles), B (structural design), H (foundations), T (fire protection) and V (space heating) of SANS 10400 must also be taken into account when constructing floors.
The Application of the Regulations relate to:
- floors in wet areas as specified in the Act (that must be water resistant)
- suspended timber floors that are not exposed to the elements
- floors and slabs supported on the ground
- all timber used for building
There are some useful drawings that show how suspended timber floors should be built.
There are also specifications for maximum spans of floor joists:
- for those made with sawn SA pine for single- and double-storey houses
- for those made with laminated SA pine, Grade 5 or higher, also for single- and double-storey houses
Additional floor specifications relate to:
- Flooring boards that must comply with SANS 629 and amongst other things should have a face-side width of at least 50 mm and not more than 140 mm, and tongued on one edge and grooved on the other, with square-sqwn or end-matched ends; and have tongues and grooves that produce a tight-sliding fit, and a flush joint on the face-side of the boards.
- Strip flooring that amongst other things should have a width between 35 mm and 90 mm and a nominal length of at least 460 mm (and tongues and grooves as above).
- Particle board that should comply with SANS 50312 and SANS 1931.
- Composite and plywood that should comply with SANS 929.
Additional guidelines relating to suspended wooden floors relate to the clearance between the joints and ground; ventilation; metal masonry anchors to be used and so on.
There are also a number of guidelines given for floors that are supported on ground or filling, but it is also stated that this type of floor should be designed and constructed in accordance with the requirements of SANS 10109-1 under the direction of a competent person (civil engineering) unless the building is to be used for storage or industrial purposes, in which case different guidelines are given.
This section also gives guidelines for underfloor membranes and filling beneath floors. Apart from anything else, a competent person (civil engineering) “shall design and inspect fills where the maximum height of fill beneath floors, measured at any point, exceeds 400 mm”.
So even if you go the DIY route, you’re going to need professional assistance.
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Walls
Janec.
Thank you for coming back to me. The tiles that was lifted in one piece, had cement stripes/ markings on the back. The tiler must have “combed” the cement and then laid the tiles, not the spot method, but after about 5 years the cement just did not keep holding on to the tiles!? No chunks of cement stuck to the tiles.
Hi Uda, This is due to bad workmanship. This seems like the tiler skimped on tile adhesive and did not put adhesive over the full underside of the tile but used the 5 spot method – a spot of adhesive on the 4 corners and one in the middle leaving gaps in between. That is why you can hear hollow taps. This is never reccomended as the tiles can crack and lift over time.
I have a house built by Garden Cities. My snag list had hollow tiles mentioned – numerous were located. I was told that hollow tiles were not a problem but should a problem arise in the future they would deal with it – unfortunately only verbal. 5 1/2 years later a large section of my open plan area has now lifted and the developer says its not their problem. Is there anything I can do?
I bought a house which was 5-6years old. About half the tiles in the living area sounded hollow to a tap; in some places the grout was breaking up as well. Tile tiles in other areas were fixed well eg on the stairs.I was advised to have all the tiles lifted and have the living area retiled. Though the tiles were quite thin (cheaper quality),about a third of the tiles lifted were not broken and had no chunks of cement sticking to the back.
Could you tell me why the tiles in a relatively new house can become loose like that?
Thanks for your help!
we are wanting to lay a 7m x 7m concrete slab separate to the house as a base for a braai area (No walls and no roof). There is no electrical or plumbing requirements. Are we required to have plans made for it?
Hi Noni, Installation of finishes by a private company are not covered by the building regulations. This is a legal matter between yourself and the installers and you should consult an attorney ar there is a fair bit of money involved here. You could also contact one of the consumer bodies here: http://www.southafrica.info/services/consumer/consumer or you could consult a consumer complaints expert here : saconsumercomplaints
we bought vinyl wooden floor and had it installed with under floor heating, within a month the vinyl started bubbling up, we called the company and told them to fix the floor, they uplifted the entire flooring and the heating, after several specialist coming to check, they realized that there is moisture underneath. now we need to know if we can force them to fix the floor, we have decided to put porcelain tiles instead, can we force them to buy the porcelain tiles and install as we have paid over R28000 for the vinyl and cannot really use it due to the moisture in the bedrooms. did they have the responsibility to check before installing that the floor was suitable for the wooden vinyl floor?
we do not want to pay again for the heating and the new floor, surely they must meet us halfway at least with the costs. please help
It’s the builder’s responsibility to do the levels and finishes. It is the responsibility of the competent person (could be an architect or an engineer) and the local authority building inspector to check that these are done correctly.
First lesson: Always use qualified builders. Second lesson: Only qualified registered plumbers should be used – that’s the law. Third lesson: Go back to the first and second lessons and employ people fully qualified and equipped to do the job. Cutting corners is more costly than doing it right the first time.
Pierre neither Part H: Foundations nor Part J: Floors of SANS 10400 mention garages. Garages are mentioned in Part T: Fire Protection. e.g. doors to any garage have to have a certain fire resistance. There is also a clause that relates to parking garages for more than 10 cars that states: “The floor of any occupancy classified as J4 shall be of non-combustible material and shall be not less than 10 mm lower than the threshold of any door leading to any adjoining room or space.”
There might be some sort of municipal by-law – your local authority will be able to advise.
It really doesn’t matter where you are laying the screed. A suitable mix would be 130 litres of concrete sand for each 50 kg of cement + enough water to produce a nice, workable consistence.
What is the right mix for screed in a public toilet?
Is this correct? I am under the impression that a garage floor must be at least 80mm below the floor level of the house where there is direct access from the garage to the house. As for “oil stores” this prevents burning oil etc. from entering the house. Maybe the by-laws differ between the municipalities.
That is called homework and you have to phone the timber and concrete suppliers and get prices from them and then compare for yourself, we do not do quotations etc, sorry.
What is the cost of using timber vs concrete to floor the second storey
The gap in the foundation walls usually gets filled with cement/mortar or concrete and then the walls above the slab should have a minimum 50mm cavity and be built with wall ties evenly spaced throughout.
there are no regulations stating that a garage floor must be higher or lower than the rest of the house. The regulations for Foundations Part-H say that the outside ground level must be a minimum of 150mm below the DPC (Damp Proof Course). The DPC is the plastic waterproofing strip that is built into the wall between the foundation and the brick wall.
Hello
What are the regulations regarding garage floor with an integral door to the rest of the house? I seem to think it needs to be 150mm below but would it serve the same purpose if it were 150mm ABOVE the house floor. It is an old house and the ground level outside is the same as the floor into the house – there is no step into the front entrance.
Many thanks.
Hi id like to know in a project whose responsibility is it to do levels or finish floor levels between the architect and the engineer..??
Good day, I am extending my house by 40 sqaures, just an extra room and en suite. On the plan it says the exterior wall should be 280mm, which means it should have a gap of 50mm between inner and outer bricks. When I checked after thd builders were done, the gap is only10mm. They have laid the foundation concrete and juat built up a couple of courses, the slab has not been laid yet. Could they still build the cavity wall with 50mm gap from the slab upwards or must the same gap / cavity be from the very first course all the way to roof height?
Hi, we’ve build a second storey with timber and it wasnt done by qulified builders, however they have years of experience.
We having endless problems with the shower, with water running down to the ground level. I’ve had several plumbers in to fix the problem that created more problems on the ground level. Now we have cealings that need to be replaced everytime it happens. We’ve stopped using the shower due to the fact that we cant find someone that knows what they doing. Advise please.
Keith if you are using a solid building material e.g. bricks and mortar or even timber-frame, your local authority is likely to require plans. There is also the issue of classification or use of the area. This needs to be specified on the plans. But the municipality has the authority to either call for plans or decide that it is “minor building work“, in which case plans won’t be needed.
Do plans have to be submitted to local municipalities for the partial enclosure of a patio?
Marnus, presumably if you are designing a “parking space” you are a competent person and therefore know or have access to this information. The only advice I can give comes from the definition of “storey” in the NBR:
a) the ground storey shall be taken as the storey in which there is situated an entrance to the building from the level of the adjoining ground or, if there is more than one such storey the lower or lowest of these,
b) a basement shall be taken to be any part of the building which is below the level of the ground storey,
d) the height expressed in storeys shall be taken to be that number of storeys which includes all storeys other than a basement
You will find the full definition in Part A of SANS 10400.
Hi, What constitutes as a “Basement”? Is there a certain percentage of the space that needs to be below “Natural ground level”? Or as per the building regulations, is it just a space below ground floor? If so, then what qualifies as the “Ground floor”?
I am designing a parking space that is mostly underground, would that count as a basement level?
Thanks!