Inspect Your Lapa To Make Sure It Is Safe
A while back a client asked me to inspect his thatch lapa which appeared to have serious defects. He had moved into his new home in February 2018. He later realised that his lapa may be structurally unsound and unsafe.
Many homeowners know very little about the lapas they have around their swimming pools and in their gardens!
The thatched roof
Obviously, the thatched roof is the most important part of the lapa because it keeps you dry! But did you know that thatch roofs should have a roof slope of 45˚ or more to perform properly?
At 45° water will run off from the thatch with minimum penetration into the thatch. At a pitch of less than 45° the thatch will decay rapidly. Furthermore, the thatch will absorb the water increasing the weight on the support structure!
What about the thickness of the thatch?
This is where many lapas have shortcomings! Well compacted thatch should be at least 175mm thick! Also, the thatch thickness should not be more than 250mm! Individual stalks of grass are difficult to pull out in well-compacted thatch.
There are also structural issues to consider!
Check for treated poles! Untreated poles are illegal.
Each pole/treated timber piece will be tagged with a code beginning with “H” and followed by a numeral digit, below is a list of the Hazard Classes with a match to their end-use applications.
- H2 – This timber is suitable for internal use, such as roof rafters.
- H3 – This timber can be used externally, but only above ground.
- H4 – This timber is suitable for in-ground applications, such as fencing poles.
The lapa support poles (posts) should not be further than 3.5m apart. Posts are the poles that go into the ground that holds the whole structure up. The posts planted in the ground should also be specially treated poles (H4) to withstand insect and moisture damage.
All pole posts should be a minimum of 125mm diameter at the thin end!
The ring beam poles used to support the rafters should not be less than 125mm and should be fixed to the top of the support posts with a sharpened 16mm threaded rod driven into the top of the post.
Furthermore, the poles used as rafters in your lapa should not have a diameter of at less 100mm at the thin end. In addition, the rafters should not be further than 900mm apart!
Every 2.7m (every 4th set of rafters) along the length of the lapa the bottom of the rafters should be connected with a king post and a tie beam to form a roof truss.
What about lightning conductors
Although a lightning conductor is not compulsory, your insurer may insist on the installation if you have a very large lapa, and it might be a good preventative measure, especially in Gauteng with its frequent thunderstorms.
If your lapa requires lightning conductors, the conductor must be installed in accordance with the SABS Code of Practice.
Your lapa may be illegal!
The lapa is an illegal construction if not shown on your approved municipal drawings. Check your approved drawings and do the right thing if it is not! If your lapa is illegal your insurance will not cover your lapa and its contents!
The SANS 10407: 2016 Edition 2 specification pertaining to thatch roof construction and SANS 10400 (National Building Regulations with special reference to part L) govern the compliance of all thatched roofs and lapas. A registered professional engineer will design building plans and approve the construction of your lapa. The formal approval must be clearly visible on the design drawings. A competent person must sign and approve the drawing!
Your boundary walls
Many boundary walls have lapas too close or against them. South African building regulations stipulate that any thatch roof covering a roof-plan area greater than 20m² must be constructed at least 4.5m from any boundary. This is to prevent a fire from spreading to your neighbour. Special safety requirements must be taken to ensure adequate fire safety if a thatched lapa is within 4.5m of a boundary.
You can build a thatched lapa with a roof plan area of less than 20m² up to 1m of the boundary. However, this is providing the lapa is a non-habitable structure (meaning that you don’t entertain or live in it)! A lapa should not be attached to any other structure. This applies to both your property or your neighbour’s.
Who certifies your lapa?
After completion of the structure, a competent person must certify that the construction complies with the SANS 10407 specification. He or she will issue a certificate of compliance if the structure is acceptable. A competent person is normally an engineer.
You will then receive an A19 Certificate of compliance confirming that the lapa complies with all standards and regulations. Without such a certificate the municipality will not sign off the structure for approval. The building inspector will also issue a Completion Certificate from the Municipality when all requirements have been met. Without this certificate, you should not buy or sell the property.
So, when buying a home make sure that you receive the approved plans for the property including the approval for the lapa! You will have to have it approved if it is not! Moreover, you may need to repair the lapa before it is approved!
Better still, the company or person erecting your lapa should be registered with TASA ( Thatchers Association of South Africa). Thatchers registered with TASA all comply with the requirements and standards of a quality thatched lapa.
Inspected Once, Inspected Right!®