Feature/Bricks & Blocks 55
So much for tests but what do developers themselves think of Hanson’s system in real site conditions? Robert Fleming is contracts manager of Norwich-based JS Hay which annually builds around 150 housing units, mainly for housing association clients, in Norfolk and Suffolk.
“JS Hay has been very successful and a lot of this is down to the use of thin joint construction,” he says. Social housing clients demand the use of MMC and many developers respond to this by opting for timber frame. “We’ve found thin joint mortar more effective than timber frame having worked with the system for up to three years now,” says Mr Fleming. “From design to site, a timber frame construction requires a 16-week lead time. With thin joint masonry this comes down to five days.”
The system was straightforward for bricklayers to learn and once they got used to it they preferred it, he says.
This ease of adaptation to new methods – something which the construction industry has not always been noted for – is born out by small housebuilder Mark Clarkson, joint director of Filmark Homes of Chapletown, near Sheffield. His firm builds just a handful of houses each year. “What I like about the system is that you can put something up more quickly but using the same skills. It’s very easy to learn and where necessary we train the sub-contractors ourselves,” he says. He goes on to offer a thought as to why more firms are not using the thin joint system. “I think it would take off more if the big companies trained their lads properly,” he says.
And why do both of these developers prefer Hanson’s Thermalite Thin Joint System to other proprietary systems on the market? “It’s cost,” says Mr Clarkson. “I find Hanson cheaper by around £1 per metre.”
Mr Fleming nominates two other reasons. “Hanson’s service to us as a customer is second to none,” he says. He also finds with the Thermalite blocks that their tolerances are tighter and this is a crucial point with the thin joint system. “With only a 3mm joint you cannot tolerate discrepancies in block size. There just isn’t the depth of joint to soak it up.”
The Percy Howes test report also noted that accuracy was key to making the system a success, beginning with the laying course as any deviation from level and line could not be easily corrected in subsequent thin joint mortar beds. This clearly presents a challenge for house builders but it is one that is necessary to fulfil the MMC ‘creed’ which, according to the Government, “makes more effective use of materials, speeds up housing delivery, enables high standards of design quality and can help reduce resource consumption.”
One major advantage of the thin joint system is that once the shell of a house is built and the roof sealed internal work can begin in a weatherproof environment leaving the building’s outer skin, whether conventional brickwork, timber cladding or whatever, to be completed when convenient and when the weather permits.
This in itself raises a further challenge for builders in that they have to adjust their sequencing of trades to cope with the fact that the build process is much speedier. The thin joint system clearly demands greater discipline from those who use it, in return for which it offers tangible rewards. Paul Dewick, director of Irvine-Whitlock, a former winner of the specialist brickwork contractor of the year award, says: “Using thin joint systems requires a different mind set but we’ve found it a very effective use of resources.”
If the industry is to stand any chance of delivering the Government’s call for a 20% increase in housebuilding then thin joint is a method that will demand further, serious attention.
Hanson Building Products Enquiry No.44
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76