Can damp cause structural damage?

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can damp cause structural damage

Damp can cause many problems in a property. The majority of these are cosmetic issues and whilst unsightly, they do not cause serious damage to the structure of your property.

However, there are instances where water ingress and damp can cause more serious problems. In this article we will be looking at how damp can cause structural damage to your property.

There are two main ways that damp can cause structural damage to a property:

  1. Rotting structural timber. this usually comes in the form of wet rot. Overtime, if timber in your property is exposed to excess moisture, rot can form and cause serious damage to structural timber

  2. Water damage to masonry. The brickwork and mortar in most properties are porous materials. This means that water can travel through the masonry. Usually this is not an issue. However, prolonged exposure to water over longer periods can cause structural damage.

Ways damp can damage structural timbers

Structural timbers in a property include things like floor joists and roof timbers. These are obviously very important to the structural integrity of your property.

If structural timbers do become damaged, they can pose a serious risk to injury. As well as being very expensive to repair.

The main way these types of timber are damaged by damp, is through the growth of wet rot. This is a form of fungus that grows in damp timber.

Once wet rot takes hold, it releases spores which spread through the timber, breaking it down to produce food for the fungus.

When left untreated wet rot can completely breakdown the timber. This can be seen in visible deterioration of the wood.

Common signs of wet rot include:

  • A damp musty smell
  • Discoloration and in some cases bleaching of affected timbers.
  • Timber becoming soft and spongy to the touch when wet
  • Where timber has dried the wood will become extremely fragile. It can often be broken and crumbled with your bare hands.
  • Movement or bounce in areas of flooring.

What are common causes of wet rot?

wet rot is caused by excess moisture. This can come from building defects such as penetrating damp, leaking roofs, or rising damp. As well as internal issues such as burst or leaking pipes.

Wet rot commonly forms in timber with a moisture content of above 50%. This level of moisture provides the ideal environment for wet rot to spread.

One of the most common areas you will find wet rot is in floor joists. This is often noticed due to movement in areas of the floor when walked on.

In many properties, this will happen at the end of the joists where the timber meets the brickwork. The timber will usually become wet due to some form of penetrating damp.

This is particularly true in older properties where the floor joists are housed into the brickwork. In this case the ends of the timber are sat inside the brickwork.

If there is excess moisture the ends of the joists will slowly decay overtime. Eventually this will mean the joists lose all structural integrity.

Obviously if issues like this are left untreated, they can become very dangerous. In the worst case scenario, it would be possible for the entire floor to completely fail and fall through.

This could be extremely hazardous and in the worst case may lead to serious injury or even death.

How damp damages masonry over time

As we have already mentioned, the masonry in your property is porous. This allows water to travel through the brickwork and mortar.

Usually this is not an issue, as the amount of moisture entering the masonry is limited. However, in some cases the masonry can become saturated. This is usually the result building defects.

The most common defects that cause water ingress in masonry are penetrating damp and rising damp.

Penetrating damp is any form of water ingress that enters the property through a building defect. This could include:

  • Cracked and damaged brickwork
  • Old pointing
  • Damage to outside renders
  • Roof defects
  • and many other issues

Essentially, if the water is penetrating in from outside this would be considered as penetrating damp.

On the other hand, rising damp is where water is rising from the ground. This is slightly less common than penetrating damp. It is usually the result of a failed or non-existent damp proof course.

A damp proof course acts as a barrier which stops moisture from rising into your property.

Your damp proof course will usually be in the mortar approximately two bricks above the external ground level.

If the damp proof course is damaged water can travel up into the property.

Water inside brickwork can cause damage overtime. This happens in several different ways.

Firstly, the excess moisture exserts pressure inside the masonry. This can cause a process known as spalling where areas of the masonry start to fail.

This can be seen with brickwork becoming more fragile. It can even start to crack, flake and crumble away.

Most of the damage will be caused during freeze/thaw cycles. This is where the moisture inside the brickwork expands and contracts. Overtime this can cause serious damage to brickwork, which could lead to structural issues.

Ways to avoid structural damage caused by damp

Structural damage caused by damp, can be avoided by using preventative measures.

For damp to cause serious structural problems, it will need to be left untreated for long periods of time.

In most cases the signs of damp should be noticeable before serious damage occurs.

It is also worth noting, if you do identify the problem early, it is quite likely that a DIY solution will fix the problem that is causing damp. even if you must hire somebody to help resolve the issue, it should be a small low cost job.

However, if you do leave these types of issue and structural damage does occur, the repair work could be much more extensive.

Below you can see links to two of our popular articles on penetrating damp and rising damp. Here you will learn how to identify both types of damp as well as some of the common ways you can stop these issues.

Learn more about penetrating damp here

Learn more about rising damp here

If you already have structural damage

If you feel like you already have structural issues, then it is highly advised that you have a damp and timber survey.

These types of survey are carried out by an independent surveyor. It will identify any areas of concern, as well as suggesting the recommended treatment.

You can save money on this type of survey by comparing local quotes.

We highly recommend a company called Bark for this type of comparison. They get you up to five quotes from local surveyors. Due to this the prices can be very competitive.

Also, every surveyor will have a profile with reviews from previous customers. This means you not only get a really good price, but you also know you are hiring a highly rated professional.

To get up to 5 damp survey quotes click here