Grease and fat in drains is a nasty problem and can cause a lot of trouble for your drainage system. Blockages can cause your drain to back up, so when you experience heavy rainfall or have your washing machine running you could find water flowing out of your drain and rain pipes and flowing in to the garden, street or even your windows and doors.

The first thing we have to ask is where does the grease and fat come from? Every time you wash pots and pans or use oil based products in the bath or shower you deposit a small amount of grease and fat into the drainage system. When the water leaves the system it has to work it’s way through traps (you can see these under your sink) and into the drainage system.

There is cold water in the trap and drain, so when the warm oil and fat hit the cold water it solidifies. This solidified fat is tough and can set as strong as mortar when mixed with silt and debris. If the blockage is quite bad you can sometimes see the fat in your back drain, which will look like a dirty white rock – it can often smell sulphurous as well.

There are a number of home made remedies that you can use to help break down the fat, including boiling water, baking soda and even a bottle of coke. However, this may only work if you have a partial blockage, meaning water is still trickling through. Drain rods, which are available at DIY stores, can also help with unclogging the problem, as well as a plunger. It can often be worth trying these before calling a professional as the problem could be minor.

You can also purchase chemicals to break down the fat, however we advise using these with caution. They may work with near by blockages – such as in the trap, but if the blockage is further down or outside you may find that this will not work. Some blockages could be as far as 10 metres (or more) down a pipe, which means a bottle of degreaser probably isn’t going to work.

If you have tried everything you can to remove the problem, but it’s not worked, then you will need to call a drainage professional who will be able to identify the problem and remove it.

You can reduce the chances of this happening by limiting what goes down your drain. Ensure that you have properly scraped your food away before washing – that includes the dishwasher, and try to limit how many oil based products you use in the bath.

If you do have a blocked drain and you’ve tried everything you can to unblock it then please do get in touch.