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”.
>
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.
>
Walls
Fatima if you look at Part J of SANS 10400 – some of which is covered in the link I have given you – you will see that there is a section for Floors supported on ground or filling – that gives some information. Wood though is not mentioned specifically and the method you mention isn’t either. If you Google “wooden flooring on concrete” you’ll see there are various ways including something similar to what you describe but using “sleepers’ underneath which I presume would be quite hefty – and they would need to be to carry the weight of the wood. You could probably also screed the concrete with mortar to which a waterproofing compound has been added and then paint with bitumen and/or use a DPC and then place the wood on top. A problem with sleepers/strips etc is that these affect the height of the ceiling from the floor. BTW I presume you are talking about using the “wood planks” (floorboards) that were originally fixed to the joists. Many modern wood and simulated wood products are manufactured to be attached directly to a screened (so it is smooth) concrete surface. Sorry I can’t be of more help.
Hi, I live in Pretoria and I removed the joists which upheld the wooden floor above my basement. The basement and the room above now have a concrete roof/ floor. I would like to re- use the original pine wood planks over the concrete slab instead of tiling. I’m told that solid wood must be placed on top of wooden strips that are nailed into the concrete yo prevent rotting and promote circulation of moisture. Could you please provide your technical suggestions or recommends in this regard? Many thanks, Fatima
In the National Building Regulations themselves it states:
“Any suspended timber floor in a building shall be provided with adequate under-floor ventilation.”
SANS 10400, Part J Floors (which is the SABS “deemed to satisfy” regs) states:
“Ventilation of the subfloor space in suspended ground floors shall be provided by means of openings spaced not more than 2,4 m apart with at least one opening within 0,75 m of each corner. The total area of ventilation openings provided shall be not less than 1 000 mm2 of unobstructed air passage per square metre of floor area. All ventilation openings shall be fitted with corrosion- resistant screening of nominal aperture that does not exceed 1,2 mm.
NOTE A 0,220 m × 0,170 m airbrick has an unobstructed area of between 0,006 m2 and 0,009 m2. Accordingly, one such airbrick is required to serve between 6 m2 and 9 m2 of flooring.
“Floor joists in suspended ground floors shall be set on and skew-nailed to sole plates that have minimum dimensions of 38 mm × 76 mm on top of sleeper walls (see figure 2). Sleeper walls shall be provided with sufficient openings to ensure good cross ventilation.
NOTE At the junction of solid and suspended floors, e.g. at verandahs, ventilation pipes might have to be provided underneath solid concrete floors. Where sleeper walls are used, ventilation openings of size at least 115 mm × 75 mm spaced at 1,0 m centres should be provided.”
Hello,
What are the regulations regarding wooden flooring and Air Bricks/Ventilation?
Should all houses with wood flooring have air bricks or some type of ventilation?
Hi Patrick, If you want to build a second storey on a single story house then the first thing you will have to find out is how strong your foundations are and if they can take the weight of a second storey. Timber is a much lighter material and many houses have a second storey built with timber. The timber materials have to be specified by a “competent person” and approved by council.
I want to buuld a 2nd storey … not sue if I should go wood or concrete…. what is best …. and can I build the 2nd floor with wood what would be the consequence in s.africa
This is clearly a case of shoddy workmanship, however I don’t there is much that you can do except name and shame the developer – e.g. on Hellopeter.
Hi there.
I purchased a brand new flat from a develloper. After 14 months the tiles started coming loose and the grout falling out. The developer states that he has a 6 month warranty and after this time takes no responsibilities for defects. Is there some sort of law i can use to make him fix the tiles without me having to pay for the damage?
Hi Dean, the regulations do say the the minimum height between the average surrounding ground level and the top of the internal floor slab is 150mm. Normally you would not have a 150mm step down through a doorway. There should be a landing or patio that leads out through the door then a step or steps down.
Rajen it depends what your contract states. If it was to be skimmed or screened so that it was smooth this should have been specified. However if it is really sub-standard then you might have recourse via the Consumer Protection Act.
Christine the floor would need to be constructed as shown on this page for suspended wooden floors. I am assuming that the fact that two families live in the dwelling is a factor – probably due to noise. This is not covered by the National Building Regulations.
Subject:
Concrete Floor Alignment
Message:
Hi
I have just purchased a brand new two bedroom apartment and a garage,I paid cash for the Garage R55000. The garage was handed over as Voetstoets ,the flooring is concrete : rough raw finish , not skimmed straight and smooth as i expected to be.Hills and valleys on the floor
Is there any regulations regarding my complaint.
Could you please advise me on the legal requirement for a wooden floor in a double story dwelling. There are two separate families living on either level.
Hi,
Please could you advise what the regulation is with regards to having an allowance between the internal and external floor levels. I’ve been told it needs to be 150mm, but this seems a bit excessive.
I have been told my 30mm height is not up to building regulations.
Thanks
Dean
Gareth all the information given in the NBR relating to suspended wooden floors – including spacing of joists (which are the beams) – is in the article on this page.
hi there
What is the requirements to build a woodern floor the maxium distance between beams
thank you
Hi Lewis,
This sounds too complicated and risky to ask and to answer in a post such as this. I suggest that you contact an engineer or another “competent person” to give you on site advice as this sort of fix needs to be done wtih the safety of all users in mind.
Hi,
We have a floor (first floor) of rib and block, the builder has placed a concrete stairway from ground floor going 90 degrees to top floor. The height from step to ceiling on the third step is only 180 cm, therefor will not pass building regulation. My question is that when I cut a piece of the upper floor away, can I then use square steel tubing to support the above floor, and if so can I fix it from the third step to the ceiling (most likely place to put it), and lastly what is the thickness of steel that I must use?
Thanks in anticipation.
Regards
Lewis
Hi Richard,
It’s not clear from your description if you are on the ground floor or not. If you are on the ground floor then the “crawlspace” (the open space between the natural ground level and the beams) will need to be filled in and compacted before your damp-proofing, reinforcing and concrete floor is placed. This is not a small DIY job. As it is a block of flats then you will have to get approval from your body corporate first. If you are not on the ground level then it all depends on how the building was constructed. Many older buildings did not have concrete floors separating them. I would advise you getting an engineer in to inspect and let him/her decide if this can be done.
Hi.
I live in a flat which is 80 yrs old.wooden floors on beam
My question is,can I remove the wooden floors n screed to
Level n then tile
Thanx
Very nice blog post. I certainly love this website. Keep writing!
There’s no law as such Willie, only SA National Standards (SANS) that govern things like how tiles are made. The way tiles are laid has to do with good building practice and not “the law”.
There are however safety aspects that must be followed – e.g. floors should not be slippery – and you will find these requirements in the building regulations under Part D, Public safety and in the Occupational Health and Safety Act.
In terms of the number of showers and toilets required, this depends on the type of building occupancy that is specified in General principles and requirements. I have recently replied to the same question at least twice. Have a look at these links – scroll down to Seelen’s query & Elizabeth’s query. They should give you more information.
Hi,
What will the law say about tiling of floors and walls? And how many shower and toilets for 20 persons?
Julien, any steps or stairs must comply with Part M of SANS 10400 (Stairways).
For a single step, the important elements are:
1. The rise of any step shall not exceed 200 mm.
2. The going and width of any tread shall be not less than 250 mm, provided that where the stairway does not have solid risers, each tread shall overlap the next lower tread by not less than 25 mm.
There are drawings on the page I have given as a link.
Hi Lijan,
Are you saying that the clause was crossed out but you did not initial it? If this is the case, you did not agree and therefore you do have rights to the CPA.
SABS 082 is an “old” regulation. SANS 10082, Timber frame buildings was published in October 2007 and supersedes SABS 082:1988 (second revision). I suggest you visit your nearest SABS office and have a look at the document – better, still, purchase a copy from the SABS – It costs R329. If there is no certificate of compliance – then surely they won’t pay out?
Good luck. Let us know what happens.