Everything you need to know about finding a Damp Proofing Expert

Damp proofing is simply the action that is taken in order to prevent moisture traveling through a wall or a floor.  It is important for a home to be correctly damp proofed in order to prevent problems such as mould, odour, termite infestation, rotting timbers, and other forms of structural damage to the home. 

Types of Dampness

There are generally five types of dampness that are found in people’s homes.  These are:

• rising damp or salt damp in brick work and masonry
  
• poor drainage
  
• falling damp
  
• condensation dampness
  
• horizontal penetrating dampness

Causes of Dampness

Damp in the home can be caused by several things including:

• Inadequate sub-floor ventilation – a lack of ventilation in the sub floor causes a build up of humidity and minimal evaporation from the soil and base walls.  This leads to rising damp, condensation dampness, and rotting of floor timbers.
  
• Sub-floor obstructions – any debris in the sub-floor can obstruct the flow of ventilation and it may also contribute to dampness by actually bridging the damp-course.
  
• Poor drainage – poor drainage can be caused by such things as built up garden beds, sloping grounds and falling damp.  If this occurs, water may be directed underneath the house.
  
• Damaged guttering and pipes – if storm water pipes, roofs, gutters or down pipes are damaged in any way, this will cause excessive leaking which leads to falling damp.

Methods of Damp Proofing

Following are some damp proofing methods that may be used on a home.

• Chemical impregnation under gravity – in this method, holes are drilled into the mortar lines at regular intervals.  Special tubes are then placed in the holes and liquid makes its way down the holes under the influence of gravity.  Once a sufficient amount of liquid has entered the holes, it creates a horizontal water repellent layer in the bricks and mortar.
  
• Chemical injection under pressure – this is similar to the above method, only the liquid is pumped into the holes rather than settling in at its own pace.
  
• A physical damp course – firstly, a line of bricks is removed from close to the floor level of the home.  A plastic sheet is then placed there and the old mortar is replaced with waterproof mortar.  Only short sections of the wall can be treated at a time, and each re-mortared section needs to set for 48 hours before it can safely take the weight of the wall again.
  
• Replacing plaster or plasterboard – with this method, the professional will take the affected plaster or plasterboard completely off the wall, right back to the brickwork or structure of the wall.  It is then replaced with a waterproof plaster or cement mix or waterproof plasterboard.  In many cases, battens will be attached in order to provide a 5mm to 10mm gap for ventilation.

Damp proofing professionals can provide the following services among others:

• quiet sub floor ventilation
  
• rising damp treatments
  
• roof ventilation
  
• mould control on walls and ceilings
  
• underfloor and basement damp proofing
  
• air filtration

Hiring a Damp Proofer

When hiring a damp proofer, you should make sure that you shop around – getting at least three quotes for the work that you need undertaken.  Make sure that your chosen company is reputable.  Finally, ensure that the company will give you a written guarantee on the work that they undertake in your home.

How Much is Damp Proofing?

Damp proofing is one field that is extremely difficult to estimate a cost for, though a professional will typically have a minimum charge for installing a defined amount (expressed in metres) of damp course. Damp proofing can be time consuming and involved work. Otherwise an hourly rate will be charged which will cover prep work, installation and replastering. If your damp problem is extensive and involves a lot of remedial work you can expect a quote that reflects the amount of time spent on the job.