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Pencil In A Way To Prove It’s Not Your Fault

AN increasing number of new properties have floating chipboard subfloors. Chipboard is rarely acclimatised to the conditions of the room before fitting, and in some cases is laid before the roof is on. Builders see this as a ‘safety feature’. I have been on several sites where rain had soaked the chipboard, causing the boards to swell. I always ask the builder why they don’t use old boards, and install the new chipboard when the building is watertight. I think you already know the answer!

They say this is time-consuming and costs money. When you explain the consequences of swollen chipboards, they just bury their heads in the sand. Unfortunately, the floorcoverings installer is left to work over these boards. The potential problem is that when the heating is switched on, the will chipboard move, normally shrinking. The installer then faces a dissatisfied customer, who thinks he is to blame for the carpet or vinyl having shrunk, leaving a gap against the wall.

You respond by saying it was the builder who installed the subfloor incorrectly. But, having already left the site, the builder wants nothing to do with the results of his mistake. There is one suggestion that is not guaranteed to stop the initial argument, but would give you some protection if you are taken to task.

Put a pencil line around the walls level with the skirting boards, and then at the front (building front) left hand corner place an arrow to a statement, explaining that the pencil lines were drawn along the skirting boards prior to installing the floorcovering. The reason for using the front left hand corner on every installation is that if a consultant investigates the problem, you can point out where to find the marks and the explanation. I also suggest taking photos, and if possible show these lines to the customer or to a third party, who can verify their existence and that they were in line with skirting board.

Another problem with floating chipboard is the amount of settlement in use. Most floating chipboard is laid on top of insulation, giving the obvious thermal advantage but can and very often does result in settlement, leaving a gap between the skirting board and the chipboard. These gaps can result in dust migration and another complaint from the customer. This is slightly more difficult to prove, but again if you take simple precautions, you can reduce or eliminate the problem. Establish a strict rule that all checks are made at the mid-point of each wall, and even in the corner if you wish.

Measure the gap if there is one, using either a gauge or even coins. If a one-pound coin slides underneath there is a gap equivalent to that coin or around 3mm. You can use multiple coins, but record what you use and write it on the subfloor at the point of the check. Also record it on your work sheet. If you are called back, you know where to look! Don’t forget to show the customer or his agent and even take photos. Another good practice is too record your measurement on the rear of the invoice so there is no misunderstanding. Please don’t read this and say this will take time. How much time does it take to solve a customer’s problem? Considerably more than the time to carry out these few checks.

Because the customer is aware that you have made these checks, they are more reluctant to phone with a potential claim. In addition, there is the amount of deflection when walked over. A few months ago I wrote regarding what I considered was an acceptable deflection, which was 10mm. In my opinion 10mm with some materials would be acceptable, but with rigid materials such as wood, too much deflection could result in a failure of the wood from lifting, pulling the nails out of the chipboard. (Extract from BS EN 13810-1:2002 5.1 – Stiffness – the floating floor shall be sufficiently stiff to ensure that the specified use does not cause deflection that may influence its performance).

Having said this, it is my opinion that nailing on chipboard is not the most suitable method. I would use tongue screws, which will hold more successfully. Some would say overlay with plywood, if of suitable thickness. Gluing can also be compromised by too much deflection. You must use commonsense as too much deflection will apply stress to the fixings and/or adhesive, and could fracture a tongue and groove.

CFJ Disclaimer: John Roberts or TAOFS will not be held responsible for any claim, loss, damage or inconvenience caused as a result of any information in this article. It is your responsibility to ensure you have taken reasonable steps and considered the site conditions prior to using the information in this article. John Roberts founder TAOFS (The Academy of Flooring Skills) and prominent consultant in flooring. TAOFS offers training in all types of floorcoverings.



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