Tremco illbruck guides on movement joint selection

Tremco illbruck's specification manager Simon Foy, helps to understand the criteria required to select the right type of movement joint.

Simon states there are probably only four or five major questions, at least to start with.

They start with: Where is the joint going to be used? What traffic is going to cross it? If it is mainly going to be used by pedestrians then everyone will gain from specifying a fairly simple system.

However if it is going to be crossed by plant and cleaning machinery, even if only occasionally, then specifying enters a whole new ball park.

In a busy airport, an expansion joint can be crossed by tens of thousands of people a week.

The first thing to consider is the engineer's or the architect's movement requirements within that structure.

Initial settlement probably also needs to be taken into account.

Expansion joints fitted soon after construction may prove to be 50 per cent or even 60 per cent smaller than actually needed as a result of settlement.

Then there is the function of the joint.

What exactly does it have to do? Does it have to be waterproof, fire-rated, or is it just literally bridging the construction gap and trying to appear as small and unobtrusive as possible? Minimal impact on the building is highly desirable in a movement joint considering that it may be a very small part of a construction project.

Within the scheme of things the movement joint is a small part of the overall project, after all it's just a bit of the floor package - a little piece of metal in the floor.

But if it isn't right, if mistakes are made.

It has a function and it could it really be crucial.

Sometimes the problem is that the contractor comes in and just blindly follows the plan without asking questions to verify that everything is as it should be.

Contractors who price work without looking at the fine details, or the subcontractors who take on work on the same basis, could find themselves very much out of pocket.

Movement joints can cost perhaps three times as much as necessary if the right questions are not asked at the right time.

Contractors who do ask the right questions may be able to offer a 20 per cent better price than the competition and still end up making a comfortable margin.

It's all a question of doing the job properly according to Simon.

Durability is one of the key issues.

Do you buy the best because of the volume of traffic that's going to go over it so that you get a life of the joint that will match the floor, or do you save a few quid and buy a cheaper joint be it poorer construction or the rubber insert type? Those poor joints may wear out in a few years.

Some contractors are not interested in durability.

They fit what is on the plans, no matter what.

Others more interested in repeat business take time and care to question the spec and then point out that for a little extra you can get a much better job.

If a movement joint is fitted that is not up to the job it soon looks tatty even though the rest of the floor still looks new and in good order.

When a movement joint starts to drop or fall apart, there can be damage to the floor.

There's an enormous range of movement joints and options and these products tend to be made to order.

That means that the flooring package might be obtainable in a few days but the movement joint probably won't be.

The movement joint is a specialist product.

It's not a one product fits all sort of a thing.

To specify the right product time has to be taken to react to the individual needs of a project.

Back to top