25 Jul Calculating materials & labour for profitable scaffold shrink wrapping
Scaffolders often ask me to advise them how much materials they are going to need for a scaffold shrink wrapping job or how much labour to allow. This article shows how to calculate the costs on a ‘per square metre’ basis and aims to help make your next scaffold shrink wrap job profitable and hassle free!
The information here is based on many years personal experience setting up and running multiple shrink wrap installation teams and supplying materials to scaffold companies large and small.
I hope you find this information useful. If you think others would too, please share!
1. Scaffold Shrink Wrapping Film
A roll of shrink wrap film for scaffolding is typically supplied as a 7m wide x 15m long roll of 300 micron thick, flame retardant shrink wrap sheeting. In theory this means that you can cover 7m x 15m = 105 square metres of scaffolding per roll. In reality, after taking into account areas where sheets need to be overlapped or welded around a scaffold tube I find that 90 square metres is a more realistic figure for usable square meterage per roll of shrink wrap. If a roll of 7m x 15m typically costs from £156 to £186 / roll, (depending on the volume discount your supplier can offer you), this means the actual cost per square metre for shrink wrap materials is going to be £1.73 – £2.07. (£186 / 90 square metres = £2.07).
2. Shrink Wrap Tape
If you are using a shrink wrap film that has been engineered for scaffold shrink wrapping then after heat welding the scaffold shrink wrap should stay bonded – you should not need to tape over the edge of each join to help it stick. Neverthless, I always allow for one roll of tape (100mm x 33m roll) per roll of shrink wrap film that is being used on a job. If a roll of tape costs £9.95 then the cost per square metre is 11 pence. (£9.95 / 90 square metres = £0.11).
I generally recommend a 13Kg cylinder size as these are convenient to move around a scaffolding and construction site. The amount of gas consumed will depend on the shrink wrapping gun you are using and the skills / technique of the shrink wrap installer.
A powerful gun will use 6-7Kg of propane gas per hour but of course, assuming the installer knows what they are doing, will allow you to shrink an area much faster.
Based on the most powerful scaffold shrink wrapping torch available – the Rhino Shrink Wrapping Torch – one x 13Kg bottle of gas will be enough to install 500 square metres of shrink wrap. If we assume a 13Kg bottle of Propane gas costs approximately £20 / cylinder then this equates to just 4 pence per square metre! (£20 / 500 square metres = £0.04).
How much shrink wrap should an installer be able to shrink wrap in a day is a very common question which can be difficult to give a definitive answer to as it will very from job to job.
As a guide I assume that one man should be able to install at least 200 square metres per day for most jobs. This may be reduced to an absolute minumum of 100 square metres per man per day on particularly ‘difficult’ jobs.
The difficulty of a scaffold shrink wrap job may depend on;
- Scaffold Structure – A well designed, flush scaffolding will be much faster to wrap than one with many protrusions. Similiarly, straight runs are easier than multiple facades.
- Site – Some sites make it difficult to get men and materials to the working area. This may be due to local procedures or just logistics. Central London sites or track side projects are examples of this.
- Weather – Attempting to battle wet and windy conditions will slow up the installation rate and may also effect on the quality of the finished shrink wrap job.
Based on an average of 150 square metres per man day, and a labour rate of £150/day, I normally estimate the labour cost to be around £1 / square metre.
I wrote this article, which is based on my own experiences, to help scaffolders who carry out their own scaffold shrink wrap jobs, make sure that they are taking into account the key costs involved. For most scaffolding encapsulation and containment jobs, the main ‘consumable’ items and costs are listed below;
- Shrink Wrap – £2.07 / m2 (or less depending on volume)
- Tape & Gas – £0.15 / m2
- Labour – £1.00 / m2 (or less depending on project and experience)
In conclusion, with some planning of the scaffold structure and by choosing a good weather window it should be possible to install most scaffold shrink wrap for £3-£4 per square metre. However, using poor quality materials that require visits to repair or installers who are not trained or experienced could add to this.
At Rhino we are always happy to answer your questions, just contact us. If you find this information useful, and think others might too, please share.
This article assumes that you already have a shrink wrapping gun and scaffold clips and looks at ‘consumables’ only. If you would like to learn more about the scaffold shrink wrap process, including the equipment involved, why not download Rhino’s free guide – How to Shrink Wrap Scaffolding.