FPDC has often highlighted issues surrounding drywall systems and their performance. Steve Halcrow urges members to make sure they are fully aware of the capabilities of the materials they are using.
Central to issues surrounding drywall systems and their performance is the subject of manufacturer’s test data. In order to be sure you are using the correct system for the right application you need to be checking that the system selected has been tested and that information such as fire and acoustic data is available.
Regular readers will be aware of me mentioning this subject on several occasions referring to drywall systems, but the matter becomes more complex and arguably more important when systems from different sources are combined.
The most obvious example of this is the interface of drywall elements with system partitions such as those that are fully or partially glazed, but we also need to consider elements like doors and windows, and of course critical items such as fire stopping.
The biggest enemy of quality installation in this respect is assumption. There is a great tendency for us to assume we know what will work, or how to construct something, without the need to check or double check.
Most often this assumption is rooted in familiarity arising from repeated experience, which is the irony: Sometimes the fact that we have used a particular material or component numerous times leads us to be complacent. We often assume that, because we did something in a particular way on a previous job, that it will work in exactly the same way on them all. This is NOT always the case, and should be guarded against at all costs.
The other common issue is the phenomenon of the Chinese Whisper. Information passed from one source to another can become diluted or distorted, with each new generation applying their own interpretation, until the original message is largely lost. This can be dangerous because, once again, it leads to a complacency where we feel we know something without making sure of the facts.
Returning to the example of system partitions, through my experience in visiting projects in my capacity as technical consultant, I note that often these are subject to some of the assumptions to which I refer above. Commonly built from raised floor to suspended ceiling, these systems are specifically designed and tested to work in precisely those conditions, but there are many of them available on the market and each is subtly different to the others. Maintaining the fire and acoustic performance, for instance, often relies upon mineral wool inserts below the floor or in the ceiling void, but the type, thickness and fixing details of these vary from product to product, system to system and application to application. Check carefully that you have the correct specification because I have seen numerous examples that have failed to work and have had to be re-built, just through assuming that ‘the one we used last time was good enough.’
Similarly, such systems have proprietary doors and windows available which would have all been tested with the system in question. Veer away from this tested solution though (for instance if a client wants an alternative door for appearance) and how do you know it will work? The manufacturer of the door may not have ever tested that item in that particular system, and it is likely that the system manufacturer will not have tested every available door!
Check carefully first where you stand before you find yourself in trouble. Where can test data be obtained? Who might accept responsibility for the ultimate installation? It will have to be someone of sufficient knowledge and experience, and probably carrying P.I. cover for the design. Are you taking on design responsibility? Check your contract, because once again in my experience contractors sometimes get into that situation unwittingly.
On the subject of interfaces, the junction of glazed systems with plasterboard partitions often gives rise to the question of performance substantiation, and again when you delve into the subject there is very little test data available for many of the common interfaces you will come across. Check with the system manufacturer that you are using an approved detail when you need to form this junction, and that the detail is one they recommend, so that you have the peace of mind that you are covered.
Abraham Lincoln is reputed to have said: “If I had six hours to cut down a tree, I would spend the first four hours sharpening the axe.” Careful planning and forethought is never wasted time.
I think the point is best illustrated by recounting an anecdote from a scheme I visited recently. The contractor in question had built several hundred linear metres of glazed partitions into a brand new office development which was in the process of being occupied by its new tenants. They complained about the poor acoustic performance and when we visited we found that:
a) the system used had been changed form the original specification and its performance not checked thoroughly enough.
b) The method and material used in the ceiling void was inadequate to maintain its performance; it was one they had used on previous projects and they had assumed the same conditions applied ╨ without checking
c) The interfaces with the plasterboard corridor walls were not formed correctly as the detail had not been checked with the system supplier first.
The contractor was liable for the considerable costs involved in upgrading the partitions ╨ in finished and furnished areas with tenants in situ.
Don’t be the one to make those assumptions. Don’t be the one footing the bill to put it right. Check first, then double check, and get it right first time. Sharpen your axe before you tackle the tree.
FPDC Technical Director