Why is it wet under my carpet? Identify the reason for a damp carpet

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why is it wet under my carpet

A wet carpet can be a frustrating problem. Whats more if you don’t resolve the issue in a timely manner, it could result in mould and an unpleasant smell throughout your home.

Drying the carpet can also be a challenge, especially if you don’t identify the cause of the problem.

There are several issues that could be causing water under your carpet. These include:

  • Rising damp
  • Leaking internal pipes
  • Penetrating damp
  • Spillages that haven’t been dried
  • Pets urinating in the house
  • Water dripping from above (this could even involve a roof leak)

Determining exactly what is causing the problem will require a small amount of detective work.

Locating the cause of water in your carpet

There are several ways you can narrow down the cause of damp in your carpet. This is mainly going to involve its location in your home.

The first thing you should do, is rule out pets urinating in the home and any prior spillages that may have occurred. One way to do this, is by smelling the carpet. If you do have pets and there is a smell of urine, this could be the problem. Cat urine can smell particularly bad, but there are techniques to stop your cat urinating indoors

It is also important to consider, if the damp has been present for a long time, it may have developed a smell of its own, due to mould formation. In many cases this is quite unpleasant and has been likened to the smell of cat urine.

Also, ask other people who live in your house if they have spilled anything in that area previously. These are two of the most common causes for moisture in a carpet and it is important to rule them out.

Possible causes on your ground floor

Once you are satisfied that pets and spillages are not the issue, the next thing to consider, is whether the problem is on your ground floor.

If this is the case, then you should determine whether this is a solid floor or floorboards. If it is a solid concrete slab, then you can probably rule out pipe work. Usually this would not be running within a solid concrete slab.

At this point you can narrow down the potential issue to the following:

If the wet under your carpet is located towards the edge of the room, it could be either of these two issues. However, if the damp is in a more central area of the room, it is more likely to be rising damp.

For situations where this is occurring at the edge of the room, you can go outside and try to identify any obvious signs of penetrating damp. These could include:

  • Damage to pointing and defects in brickwork.
  • Old, cracked render or pebble dash.
  • Raised ground level that is above the damp proof course  
  • Anything causing excessive water to run onto the property.

If any of these are present, then there is a good chance that repairing them could solve your problem. If they are not present, then rising damp is becoming more likely.

If your ground floor is floorboards than rising damp can still be an issue. However, it will be more isolated towards the outer walls, as well as any load bearing internal walls that come in to contact with the foundations

Need help from a damp expert?

At this point, it may be a good idea to have a damp expert look at the issue. You can find reputable companies online via specialist comparison sites.

The advantage with this type of comparison site, is the damp experts are rated and reviewed by previous customers.

Also, you will get multiple local quotes, so prices tend to be extremely competitive. Whats more, most firms will carry out a free inspection, so you may be able to get several experts to look at the problem and quote on the job.

Click here to get up to 5 local damp proofing quotes

Wet under carpets in your basement

If your issue is below ground level, then it is far more likely that the moisture is penetrating in from the outside ground. This could be either rising or penetrating damp, depending on the direction it is coming from.

If this is the case, you may need to carry out some form of tanking in your cellar. This could be quite disruptive if the room is in use. As it will require access to the walls and floor, to apply either a membrane or tanking slurry.

You can read more about tanking a cellar by clicking here

wet under your carpet on upper floors

If the issue you are facing is on an upper floor in your home, then you can rule out rising damp. Damp is only able to rise approximately 1.5m. For this reason, you can’t get rising damp upstairs.

However, penetrating damp is still a possibility. This type of damp is not isolated to a specific area, it can happen anywhere defects are present to the outside of your property.

To determine if penetrating damp is the cause of your problem, you should again carry out external checks.

The other potential cause on upper floors is a leaking or burst pipe. If this is the case, it is possible there will be signs of damp on the ceiling below. You will need to lift the carpet and floorboards to try and locate the issue.

Also, look out for any other potential leaks above the carpet. This could include:

  • Leaking radiators.
  • Issues that could be originating from the bathroom or kitchen.
  • Pipes in walls or pipes that are boxed in which could be leaking.

Obviously, if you find a leaking pipe, or suspect this is the cause, you will need to hire a plumber to fix this issue.

If you don’t know a plumber or are unable to get a recommendation from friends or family, comparing quotes online would be a good idea.

As with damp proofing experts, most reputable local plumbers are on comparison sites. This means you can get in touch with local plumbers and read reviews before you commit to hiring anyone.

Click here to get up to 5 local plumbing quotes


There are many potential reasons for damp under your carpet. Some of the most common are spillages and pets going to the bathroom indoors.

However, there are several instances where structural defects and plumbing issues can cause this type of problem.

The best thing you can do, is go through the checklist provided here and see if you can determine the issue yourself. If you can find the problem, you may be able to fix it yourself. Failing that you should hire a professional to locate and repair the issue.

In most cases there will be minor repairs needed. However, you should treat the problem sooner rather than later.

Where damp is present, mould will usually follow. This can result in an unpleasant odour, as well as irreversible damage to your carpets and other decorations.