What thickness of plastic is suitable for your project?

In our guide to choosing the right thickness of plastic we'll cover:

• Indoor projects 
• Garden furniture
• Polycarbonate

When you’re embarking on a DIY project using plastic sheets, it can be difficult to know which thickness to use that best suits the task at hand. Sometimes, there’s an easy solution. For example, if you’re replacing a broken window in your greenhouse, you can simply measure the thickness of the glass that’s already there and you’ll know it’s accurate. But if you’re starting from scratch, the answer isn’t always so simple.

Indoor projects 

Polycarbonate sheet makes a great material for use with indoor projects as it’s lightweight and easy to work with, particularly for DIY-ers. For example, if you’re looking to install a cover for table tops or check of drawer units to protect them from scratches and damage, a plastic sheet of 2mm is perfectly adequate for your needs. But if you’re looking to remove the cover each time you sit down to eat at the table, or it will be removed for cleaning on a regular basis, you may want to consider a 3mm or even 4mm thickness to make it more robust for frequent movement and lifting from the furniture.

If you’ve decided to add some floating shelves to your home, acrylic is a great and contemporary choice. We offer a range between 20mm and 30mm in clear acrylic that’s perfect for this type of project – correctly supported on the wall, it makes a great addition to any home. Acrylic also makes a great material for splashbacks in the kitchen or bathroom, as it’s easy to keep clean and hygienic, as well as long-lasting. We recommend using a thickness of 5mm when using for kitchen splashbacks, as the adhesive can show through certain colours in 3mm sheets and will ruin the appearance.

As a general rule, 2mm thick sheets can be used in any application where it won’t lie completely flat, such as non-frame type shed windows and mildly curved applications. The mild curve can be used to actually increase rigidity in this case. 

Garden furniture

Looking to add some acrylic touches to your garden? Acrylic plastic is ideally suited to outdoor use, as it’s weather-resistant and will withstand knocks and scrapes with ease. It’s also shatterproof and impact-resistant, so if you have young children or pets, you can rest assured that they’ll stay safe.

When you’re purchasing clear acrylic sheets for the garden, you need to consider what will go onto the acrylic before deciding on the thickness you will need. Is it just plates and glasses, or heavier items, and how well-supported will they be? If there’s a lot of support underneath the acrylic, for example with a cut-to-size table top that sits on a solid base, then you can choose a thinner sheet – although we would still advise a minimum thickness of 5mm – whereas if there is minimal support, we would recommend that you choose a minimum of 8mm in thickness to ensure that it stays stable.

Polycarbonate

Polycarbonate is softer than acrylic, so the scratch resistance is lower, and it may be more likely to turn cloudy over time. However, it has up to 20 times the impact strength of acrylic, so it’s worth bearing this in mind when deciding between the two for your project. If you’re using polycarbonate, we recommend a minimum thickness of 3mm for applications such as replacing shed windows to provide adequate security. If you’re replacing or installing greenhouse panes, you may want to opt for 4mm instead. We often have customers purchase polycarbonate for the roofs of pergolas, in which case the issue of support arises again. If the plastic is well supported, a thickness of 5mm is sufficient, whereas you may want to consider a thicker sheet if there is not as much support to give you the strength you need for the pergola to be secure. 

It’s important to bear in mind the dimensions of the acrylic when you’re thinking about which thickness to order. If the dimensions are small, thinner acrylic is often relatively sturdy and is likely to be sufficient. However, if you’re purchasing a larger sheet, you need to ensure there is plenty of support and this amount of support will directly impact the thickness you’ll need. While acrylic is robust, it still needs support when used in large sheets so opt for a thicker sheet when in doubt if the dimensions are on the larger side. As an example, if the sheet is up to 1.5 sq. metres, 3mm should suffice, while anything between 1.5 and 2 sq. metres should have a minimum thickness of 4mm. If you’re unsure and want some friendly advice, give our team a call on 01903 389024 or drop us an email at [email protected] and we will be happy to help you make an informed decision.