Do you need DPM under garage floor?

Solid floor
The existing concrete floor can be used as a base, however a new damp proof membrane (DPM) will need to be introduced. DPMs come in solid or liquid form, the latter being a practicable solution for a garage conversion.

Do I need a damp proof membrane under concrete?





These days, damp proof membranes are required in the construction of all new buildings to prevent rising damp. These strong and highly durable Polyethylene 1200 Gauge DPMs are sandwiched between the hard core and concrete slab to form an impermeable layer.

Can you screed over damp proof membrane?

The current recommendations for an effective damp proof membrane are that the ground should be constructed using screed with the damp proof membrane laid either on top or below that layer.

How do I stop damp in my garage floor?

If you are having issues with condensation, try the following:

  1. Decrease the dampness/humidity of the air with a dehumidifier.
  2. Increase air temperature in the garage.
  3. Change the garage floor surface – Our Garage Flooring is an ideal solution.
  4. Check door seals.

Do you need a damp proof membrane in a garage floor?





When damp proofing a concrete garage floor, a plastic dimpled membrane is required if the floor is going to be boarded (either with chipboard, plywood or similar) or if a concrete screed is going to be laid. You might consider a slimline membrane which is ideal if you intend on laying carpet over your floor.

Why is my garage floor always damp?

For many homeowners, the reason for a slick garage floor is condensation. Condensation occurs when moist air comes into contact with the cool concrete of the garage floor. Upon this meeting of two conflicting temperatures, the air begins to cool below the dew point, condensing on the concrete’s surface.

Can damp come through a concrete floor?

Damp affecting Concrete Floors
Floors can easily suffer from moisture ingress otherwise known as penetrating damp. Damp in concrete floors are much more difficult to treat than having damp walls.

Can water come up through a concrete floor?

No, water isn’t going to soak up like a sponge, but concrete does allow water to seep through when there is enough. Concrete also cracks, and those cracks will be the first routes of seeping water as it leaks through the slab.

Can moisture come up through concrete slab?



Humidity—warm and humid air condenses into surface moisture when it comes into contact with the cool surface of your concrete floor or slab. Faulty/Missing Vapor Barrier—moisture from the ground can seep up and through the concrete.

Does sealing concrete stop moisture?

Basements and garages – the typical rooms with concrete floors – also suffer from poor air circulation, giving the moisture nowhere to go once it seeps through the floor. Sealing the concrete can help eliminate the dampness on your floor.

Should a garage have a DPC?

To protect the wall from rising ground moisture, a DPC should be provided at a level at least 150mm above the level of adjacent ground.

What to put on a concrete floor to stop damp?



The easiest solution for damp proofing concrete floors is to install a plastic membrane. Essentially, this is a plastic mesh sheet specially formulated to ensure that moisture cannot penetrate. It sits between the concrete and the underlay floor covering.

How do I stop water seeping on concrete floor?

Supporting Joints
Any joints in your concrete floor also invite water to seep in, and the best way to stop water in these areas is to seal them up with exterior-grade caulk.

How do you waterproof a concrete garage floor?

7 Steps for Waterproofing a Garage

  1. Step 1: Prepare the Space. …
  2. Step 2: Inspect Your Garage. …
  3. Step 3: Fill Cracks With Masonry Crack Filler. …
  4. Step 4: Choose The Correct Garage Floor Paint. …
  5. Step 5: Apply Waterproof Paint to Garage Walls. …
  6. Step 6: Apply Concrete Floor Paint to Garage Floors. …
  7. Step 7: Replace Your Belongings.

How do you fix a damp proof membrane?



How do I install a Damp Proof Membrane?

  1. Cut the damp proofing membrane to size.
  2. Place the damp proofing membrane on the wall.
  3. Neatly fold the damp proofing membrane around the corners.
  4. Drill then fix the damp proofing membrane to the walls ensuring a tight fit.
  5. Apply wall finish to the damp proofing membrane.

How long does damp proof membrane last?

20-25 years

Typically, a physical damp proof course lasts for 20-25 years and can fail due to it not being fitted properly or deterioration. If a damp proofing course has failed then this could potentially lead to rising damp. Rising damp is the movement of moisture through the walls and floors by capillary action.

What is the difference between a damp proof course and damp proof membrane?



The damp proof course may be horizontal or vertical. A DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall. A damp-proof membrane (DPM) is a membrane material applied to prevent moisture transmission.