Frequently Asked Questions

Apart from being able to use people who have never constructed a dwelling before, the speed of the process allows very productive and profitable results. From a social perspective, Stumbelbloc allow unskilled workers – even if they are unable to read or write – to both make and build with the blocks without any energy or power source. Some simple tuition is all that’s required. Blocks can be made in remote areas (Including disaster zones) providing that local sand and cement is available. The resulting structures providing permanent and very robust accommodation.
Yes, any sort of concrete or plaster sand may be used but the finer the sand the weaker the finished block will be. Sand containing any organic material or salt should not be used. River sand is preferred. Sand with best properties comprise of particulars that has a variation of fine to coarse sand grains and must have no clay form.
The blocks can be made with any material that can bond with cement. As stated previous, the strength of the finished block will depend on the material used. For example, volcanic sand/any crushed rock material is ideal when mixed with cement. Please note: ORGANIC material is not suitable for making the blocks and should not be used.
Anything that is ordinarily built with traditional blocks can be built with Stumbelbloc, but with Stumbelbloc it is cheaper, faster and easier.
Ideally, yes. In order to maintain structural integrity, it is recommended that a suitable plaster is used. This not only provides a cost effective and waterproof layer to the blocks, but also penetrates the horizontal gaps between them. For thin bed mortar “Block Grip™” and “Skim Plaster™” please visit www.technicalfinishes.com
The method of building is 10 times faster than normal. A standard structure can be built to roof height in one day. No time is wasted on setting up profiles and preparing mortar mixes. The labourer carrying the block actually lays it instead of handing it to the artisan. No time is spent cleaning up afterwards. If required, several labourers can work at the same time without interrupting each other’s work.
Much less material is used than in conventional building and the labour cost is a fraction of the normal rate because unskilled labour can be used to do the work of otherwise expensive artisans. For standard openings (windows/doors) Stumbelbloc may be used in place of lintels – saving time, money and procurement/delivery costs. Finally, the use of Stumbelbloc eliminates almost all building waste. Any surplus standard mortar can be used to make more blocks.
This is determined by the block strength. 4, 8 MPa can build up to 5, 3 m load bearing walls. Maximum wall plate height is 3, 5 m and maximum gable height 5, 3 m
Stumbelbloc has been approved in South Africa for single storey dwellings only. Refer to your countries building regulations and requirements of MPa strength for different levels
This depends on how much time you have and the size of the house. A small dwelling of 58 m² needs 1 500 blocks. 60 moulds will keep 1 labourer busy daily and will produce the required number of blocks in 50 days. 2 labourers will mean 25 days etc. And so on prorate.