Penetrating Damp

As you’d guess from the name, penetrating damp can get into your property through the roof, the walls, the pointing, even sub ground areas, so if you notice any dampness, strange watermarks, suspicious growths of mould or unusual smells, you might be looking at a penetrating damp problem. Damage to timber or plaster can also be a sign. At Richardson & Starling, we are property care experts with a wealth of experience in property waterproofing.

Water will always follow the path of least resistance, and unfortunately what this means is that penetrating damp problems are caused primarily by issues with the external of the building itself. This could be anything from porous masonry or render, damage to the roof or rainwater goods to poor door and window pointing. Even changes near the house such as garden work can cause the problem to start. If you think that you might have a penetrating damp problem, you need to contact us to get a survey done! Property waterproofing is important to prevent costly damage to any property.

Solving Your Penetrating Damp Problem

The first thing which we’ll do is carry out a thorough survey: there’s no point in starting treatments for penetrating damp only to discover that the problem is something with similar appearance but a different root cause! Once we’ve established the nature of the problem, we can treat penetrating damp with traditional building techniques – repairing the damage which allows the damp in – or by applying a physical membrane or chemical water repellent.

When faced with a cottage in the north of Scotland which was showing alarming symptoms, the very first thing we did was to survey the property. The survey showed us that the problem was indeed penetrating damp. The problem was that the stonework and mortar had become porous, which meant that damp was just soaking through. Now in a normal case we might have fitted a traditional render system, but this cottage was located in an area with extreme weather conditions. Instead we used a specialist cavity membrane fitted to the external walls with a traditional render applied to the membrane. Such property waterproofing techniques, as well as others, can be implemented to prevent costly damages.
Penetrating damp repair

Causes of Penetrating Damp

First of all, we must understand what causes penetrating damp. Penetrating damp is most often caused by one of two scenarios:
  • Problems with external envelope of the building. Such examples may include a loose slate or blocked drainpipes. Penetrating damp is present where an existing problem has allowed water to enter the property in one form or another.
  • Wind driven rain. This is a real issue, especially with properties near the sea or in exposed areas can suffer penetrating damp from driving rain. Symptoms will usually only occur during wet weather – something that occurs often in Scotland – but it can affect roofs, ceilings, and walls.

Check what is Causing the Penetrating Damp

You’ll need to identify where the water is penetrating the property to treat penetrating damp, so working out what might be saturating your walls and/or ceilings with water is key. In most cases, cracks and fabric defects are the culprits to blame. Where the penetrating damp patch is found will be the primary indicator as to where to look first. For example, if the penetrating damp patch is found at guttering height, start by checking your downpipes and gutters for potential leaks. It can be easy to damp proof a house if you know where to look.
House with scaffolding
Some common places to check for causes of penetrating damp include:
  • The roof. Missing tiles, the pointing, roof ridge tiles (the shaped tiles at the very top of the roof), and flashing (the point at which a roof meets the wall or a chimney) are all key areas to inspect for causes of penetrating damp on a roof. If any of these are missing or loose, they’ll need maintenance to stop or prevent penetrating damp.
  • Window frames. These must be checked to see if there are any gaps or cracks around the frame. If there are, these should be filled with a flexible frame sealant. Also, make sure to check that there is a “drip groove” – a groove intended to stop water running onto the wall – under the window sill. If one does exist, make sure it hasn’t been filled in, and if it doesn’t, a good solution is to add a hardwood strip around 35mm from the front edge.
  • Door frames. Any cracks that exist around door frames will need repairing. In addition to this, if your external door doesn’t have a weather bar – a board that sits at the bottom of the door and protects from excessive rain – it may be time to think about fitting one.
  • External walls. Cracks in external or missing pieces of mortar (the filling – cement or otherwise – between bricks) can cause penetrating damp. If this happens to be the case, make sure these are filled with an appropriate filling material. For older buildings, a mix of lime and sand is often used as these are more porous and so will take water away from the bricks. The masonry or external render can become porous or crack with the render breaking away from the masonry allowing rainwater to get in. Get in touch with our team to find out more about what would be best for your home.
  • Home plumbing. Where possible, check the status of your pipes, particularly in the kitchen and bathroom. If they are leaking, they could cause penetrating damp to areas below the leaking pipework or through adjacent walls into other rooms.
It may also be that old bricks have become damaged and porous, allowing water access to your home. These must either be repaired or painted with an exterior silicone water-repellent or lime wash that will still allow your walls to breathe. This also doubles as a good preventative measure; better to nip the problem in the bud now at a cheaper cost than have to deal with a far more expensive fix further down the line.

Cavity Walls and Their Role in Penetrating Damp

Cavity walls can also be an issue when it comes to causing penetrating damp. A cavity wall is a wall consisting of two separate walls separated by an internal cavity or space. All modern homes (built since the 20s and 30s) have cavity walls, often for insulative purposes. This also allows for moisture penetrating the external wall to evaporate before it hits the internal wall.

The problem arises, however, when something “interrupts” the wall, such as a window or pipework. When this occurs, you may need a cavity tray. These come in many different forms but effectively act as a way to drain any excess water away from the inner wall to the outside by virtue of “weep holes” – holes in a part of the external wall.

If a cavity tray is defective, Richardson & Starling can help. Simply visit out penetrating damp costs page to find out more about pricing, or contact us for an immediate answer.
Penetrating damp proofing working
Finally, cavity wall insulation can sometimes cause penetrating damp problems. This is usually the case if the external leaf starts to deteriorate and the property has been exposed to severe and sustained levels of wind-driven rain. The damp transmits through the cavity insulation and affects the internal leaf and the fabric inside the property.

How to Identify Penetrating Damp

Penetrating damp is unsightly and can ultimately end up in costly repairs. To this end, you need to know the signs of penetrating damp so you can catch it as fast as possible. Some of the signs of penetrating damp are:
Damp proofed building wall - membrane
  • Damaged/misshapen plaster. Plaster will blister, show signs of disintegration, or show signs of “salting”. Salting is water acting in conjunction with the natural salts found in the plaster and will result in a fluff-like residue being found on the plaster.
  • Localised dampness. There may be localised patches of damp in seemingly random locations that won’t dry out, no matter what technique you use.
  • Mould growth. If there is visible mould growth or the accompanying musty smell, this may be an indicator of presence of penetrating damp which is attracting condensation mould growth.
  • Damaged internal decoration. Damp, discoloured patches on internal decorations and walls or discoloured tidemarks in line with external ground level or external envelope defects.
  • Rotting floor timbers or skirting boards. If these show signs of wet rot decay, penetrating damp is a very real possibility.

Penetrating Damp Systems for All Types of Property

Whether you home is brand new or has been around for years, we can help you install penetrating damp preventative measures. Both new builds and older buildings need to be capable of dealing with the problem of penetrating damp, as it can end up requiring some costly repairs and affect your overall quality of living. Penetrating damp has no mercy; whether a building is old or new, it will take any opportunity to deteriorate your property. Every home is subjectable to water damage.
 Experience comes with age and practice. We offer our waterproofing services to both domestic and commercial properties. We waterproof buildings by applying the appropriate waterproofing specification to the right areas to solve the damp problem. Richardson and Starling have over 80 years of experience in property damp proofing and waterproofing. We will provide you with quality services and peace of mind as you will know that your property is in the best hands. 
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Richardson and Starling are associated with high-quality methods and aapplications. This makes us the best property waterproofers in the UK, put your home in our hands. For more information on our services give us a call today! One of our friendly team will be able to answer any questions that you have.

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