Your wallpapering project could be a two or three-day job. So, mixing up another batch can be inconvenient and costly if your paste dries up.
In this article, I use my years of experience to answer the question, “how long does wallpaper paste last?” I also offer some tried and tested storage tips to extend the lifespan of your paste.
How Long Does Wallpaper Paste Last?
Typically, wallpaper paste comes in powdered form, mixed with cold water to create a thick paste.
However, some manufacturers have introduced ready-mixed paste for ultimate convenience.
Let’s look at the difference in shelf life between the different pastes.
Like this Solvite All-Purpose Paste, powdered wallpaper paste lasts for two years in its unmixed state. So, even if you’ve mixed half the packet, it will still be usable if you store it in a dry and sealed environment.
Once you’ve mixed the powder and water, it forms a thick paste. Expect it to last for two to seven days if stored in an air-tight container. If you think your project will take longer, mix smaller batches to minimise wastage.
Ready-mixed paste is the new kid on the block. Solvite’s Ready to Use Wallpaper Paste ticks all the boxes if you’re a novice or unsure how to mix paste.
Unlike powdered paste, the ready-mixed paste starts to deteriorate once you open the tub. You might get about a year’s worth of use, but it depends on how it’s stored.
Pro Tip: Store it in a dark and cool location, and never keep it in direct sunlight, as this will dry out the contents.
Can I Use Old Wallpaper Paste?
Your powdered paste may be old, but it doesn’t mean it’s unusable.
Wallpaper paste has no expiry date, but its accepted lifespan is two years, although it’s still likely to work beyond that time.
Keep in Mind: Older paste has a weaker adhesive bond with your wallpaper and wall.
The best way to find out if it’s still usable is to mix it with water and see if it still works. That’s what I did once when I found a packet of paste so old I swear it had acne. Imagine my surprise when the paste worked fine and saved a few pounds!
Using old wallpaper paste reduces wastage and is better for the planet but is it worth the risk?
Wallpaper should hang on your walls for 15 years. However, does the paste lose adherence every year beyond its expected lifespan? Only time will tell.
Signs Your Wallpaper Paste has Gone Off
So, you’ve taken the plunge and mixed that old packet of paste you found in the garage, and it’s time to hang the wallpaper.
But what are the tell-tale signs that the paste has spoiled with age? Below is what to look out for when judging the quality of your wallpaper paste:
- Loses adherence when applied to the wallpaper.
- It takes longer to cure.
- Loses viscosity (has a runny consistency).
- Shows changes in appearance (colour and texture).
- It gives off an odd smell.
- The powder crystals have several hard lumps.
How to Store Wallpaper Paste – 3 Easy Methods
Once you’ve finished wallpapering for the day, you’ll need to store the paste ready to use again.
You could throw it away and mix up a new batch when needed, but that’s wasteful. Here are three tips for preserving wallpaper paste:
1. Using a Sealed Container
Using sealed containers is a smart move. They have air-tight lids that preserve the contents, keeping them wet for the next day. Old Tupperware containers are ideal for this job.
2. Using Cling Film
Most people mix their wallpaper paste in a bucket which doesn’t have a lid.
A simple trick to keep paste fresh overnight is to wrap the top of the bucket in cling film. This method seals the paste, locks out air, and preserves it for future use.
Pro Tip: If you don’t have time to clean the pasting brush, wrap it in cling film and store it in the fridge overnight.
3. Using a Food Bag
Pouring the leftover wallpaper paste into a food bag is an ideal storage solution.
Ziplock food bags are a great choice because they’re leakproof and seal the contents to keep them fresh.
How to Dispose of Old Wallpaper Paste
There are two ways to dispose of old wallpaper paste: down the drain or throw it out with the rubbish. Neither method impacts the environment because wallpaper paste is non-hazardous and non-toxic.
Disposing of Wet Paste
You’ll need to thin the old paste with water to a runny consistency to pour it down the drain.
Run the hot tap to wash away the paste residue before it dries hard and becomes challenging to remove.
Pro Tip: You can also flush paste in your toilet but only if connected to the central sewer system. If you have a septic tank, it could block the system if it dries.
Disposing of Dry Paste
Pour the paste into a container and leave it to dry out completely. Once it forms into a solid block, throw it in the bin with your other household waste.
Remember, wallpaper paste is water-soluble and friendly to the environment, posing no risk.
Disposing the dry paste may be the best method if you have a lot to throw away.
So, powder paste lasts approximately two years if stored properly, and wet paste gives you two to seven days of useful life.
At PWS, we highly recommend investing in Solvite’s Ready to Use Wallpaper Paste as an excellent alternative to powder paste.
Knowing how long wallpaper paste lasts is crucial. After all, you want your wallpaper to stick for 15 years and more.
Check out our How to Wallpaper a Feature Wall guide to learn about wallpaper paste.