Scaffold shrink wrap is one of those construction site services that are fully dependent on weather conditions. For achieving the best final results with optimal durability, the installation requires a dry and low wind environment.
Shrinkwrap is a very unique product. Some trades can carry on in most weather. In only very extreme circumstances will the weather prevent, for example, scaffolders from carrying out their job, especially if they have waterproof clothing on. For shrink wrap, it is simply that the product itself becomes unworkable above certain wind speeds or when it is raining.
On a weekly, sometimes daily basis, we are confronted with the never-ending challenge of the weather. Right now, for example, the UK is being battered with Atlantic winds up to 86mph with some unsettled conditions likely for the coming weeks.
Many companies will expect their shrink-wrap contractor to show up on-site despite any weather conditions, install the product very quickly and also achieve the perfect finish. This is just not realistic. Not only does this pressure installers into rushing the job to keep their client happy, but if/when the client is unhappy with the result, it often then backfires at the cost of the shrink wrap company.
Getting the shrink-wrap into position is one thing. It’s the welding and shrinking of the product that is severely impacted by the weather.
When shrink wrap is in its ‘mid state’, it has been heated up to a very vulnerable form similar to the texture of a loose balloon - very wobbly, thin and prone to stretching out rapid speeds. This state is very close to the product almost melting. When this cools after a minute or so, the product loses its overall size but becomes thicker and forms the tight drum skin finish that is desired.
The problem is if the weather is windy/gusty, the wind will easily blow out these vulnerable mid-state points almost like bubblegum. The sheet will be bouncing back and forth wildly, pulling and pushing any area you try to heat in a neat and tidy fashion. The finish will not be flat and may look crinkly, uneven and thin in some areas.
Additionally, if the weather is forecast to rain, this can be a huge problem for the installation of shrink wrap. When shrink wrap becomes wet/dirty, the sheets will not weld together properly.
Have you ever tried sticking tape onto something wet or dirty? It just does not work. Even if you think it may have stuck or bonded properly, it most likely has not.
Our rule of thumb is anything above 20mph gusts becomes an issue for the installation. This can be a generalisation, other factors such as project location can also play a huge factor with wind speeds. For example, a forecast showing 20mph gusts in Brighton & Hove, you can be sure this wind speed will be slightly stronger due to its coastal location. A project above 10-15m in height will also experience the same kind of issue, the higher you go up the windier it will be.
One of the first questions I will ask someone asking for a shrink wrap quotation is ‘How exposed is this project?’
Are there trees or surrounding buildings?
Are you next to the sea or in a built-up area such as central London?
These are important questions because if the project is exposed… the customer must be aware that when the expected start date arrives, the weather forecast needs to be >20mph gusts. Perhaps even >15mph in very exposed locations. If the project is a temporary roof or quite large, this low wind will also be needed for several days if the installation is to be successful.
Which Weather Forecast to check?
Forget the BBC or Apple weather, they are very unreliable. Most importantly though the wind speed displayed does not show the maximum gusts, just a general wind speed and direction.
At EnCaPS we find MetOffice and XCWeather to be the most reliable weather forecasts. This shows more details of wind speeds at specific times of the day as well as the maximum gusts to be expected.
Utilising these weather apps whilst working with your shrink wrap contractor will help keep both parties synchronised with expected installation dates as well as a clear understanding of why there could be delays.
To learn how to set up the scaffold for shrink-wrap installation please follow: