Cannon Contractors

Damp Survey And Damp Treatment

Need A Damp Survey Or Damp Treatment Anywhere In Yorkshire, Lancashire, Nottinghamshire, Derbyshire, Lincolnshire Or Humberside?

We will carry out a damp survey anywhere across the whole of Yorkshire, Lancashire, Nottinghamshire, Derbyshire, Lincolnshire and Humberside. Our damp survey team will correctly identify the cause of the damp problem to recommend its treatment. A common problem for our customers is that they believe that they have a rising damp problem. However, on many occasions we find that throughout the course of our free damp survey this is not the case. Therefore the work is unnecessary, a waste of money, and does not solve the damp problem that they have. Did you know that 75% of buildings that have received a damp proof course did not need one? At Cannon Contractors a damp survey is free with no obligation to get a damp treatment.

Cannon Contractors are specialists in carrying out, not only a free damp survey, but also damp treatment. We have damp survey teams in the following locations;

Damp Proofing Yorkshire


Damp Proofing Lancashire


Damp Proofing Nottinghamshire

Nottingham – Covers the whole of Nottinghamshire

Damp Proofing Derbyshire

Derby – Covers the whole of Derbyshire

Damp Proofing Lincolnshire


Damp Proofing Humberside

Hull – Covers the whole of Humberside

Stop The Damp Problems Before They Happen

They say that prevention is better than the cure and that is certainly the case with a damp problem (although nothing is incurable). We can provide you with a free damp survey or damp treatment that will detail where your building is susceptible to damp problems. This free damp survey will also help to discover any existing damp problems your property may have and will allow us to provide you with a solution. which will stop any further damage happening.

Fully Trained Damp Proofing Experts

We have a skilled team of damp proofing experts and all the tools necessary to locate and fix your damp problem. When the damp problem is lateral damp, rising damp, condensation or water damage, we have a wealth of experience in damp proofing. combining over 100 years we feel that we know exactly how to treat every situation and bring it under control –restoring your property back to its best and preventing future troubles. Get in touch today to begin getting the problems sorted, before they spiral out of control. It may very well be easier and cheaper than you think.

Identifying A Damp Problem

Need help identifying a damp problem? Below you will find an interactive tool to help you identify the type of damp problem you may have along with the cause and how we can help you find the solution.

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Condensation And Cannon Contractors

condensation and black mould experts working in Sheffield, Chesterfield, Leeds, Wakefield, Barnsley, Manchester, Oldham, Bolton. We cover Yorkshire and Lancashire.

How to stop condensation on windows?

‘Condensation dampness’ is a condition that affects millions of homes in the UK. Condensation is particularly common in houses which are poorly heated and insulated i.e. have more cold surfaces and usually gets worse in winter. This problem can lead to mould growth, developing and damaging wallpaper, wall surfaces, window frames, furniture and clothing. Tiny spores are produced by the mould and higher numbers of dust mites due to the moist conditions can also increase the risk of illness such as asthma and bronchitis.

What is condensation?

All air contains an amount of ‘invisible’ water vapour. The higher the temperature of the air the more water vapour it can hold. When the air carrying vapour comes into contact with a cool surface, it reduces the temperature and it can no longer hold the water so it is deposited.

Condensation on patio doors

Where does condensation dampness occur?

The most vulnerable areas will either be rooms where a large amount of moisture is produced, i.e. bathroom/kitchen, or on cold surfaces in other rooms where this moisture can travel to. The effects of this process may be visible, for example, droplets of water on gloss painted windowsill’s, but often the water droplets will soak into the wall and a problem will not be diagnosed until black mould patches start to appear.
The following areas are particularly prone to condensation:

  • Cold surfaces such as mirrors, single glazed windows (above) and metal window frames.
  • Kitchens and bathrooms.
  • Walls of unheated rooms.
  • Cold corners of rooms.
  • Wardrobes/cupboards and behind furniture against an outside wall.
  • How to tackle condensation dampness

Condensation which has caused black mould

Why Is Condensation Considered To Be A Damp Problem?

The major difference between condensation and other forms of dampness is that you have the ability to reduce or solve the problem just through changing behaviour in the home. Try following these steps:
Reduce the moisture: Normal activities such as bathing, washing and cooking all produce moisture which cannot be avoided. Simple changes however can prove effective in tackling condensation dampness. Steps to consider are:

  • Keep lids on saucepans while cooking.
  • Tumble driers should be vented to the outside.
  • Avoid the use of bottled gas and paraffin heaters as these produce high levels of vapour.
  • Dry washing outside when possible.

However, additional steps and measures are required so it is best to get a damp expert to survey and assess the property.

Condensation which has been caused by cooking

Rising Damp

Rising damp salts on brickwork

What is Rising Damp?

Rising damp is the result of water seeping through from the ground surrounding the foundations of a building. Brick and stone are naturally porous and therefore the moisture will soak into these materials over time. Heat draws up the moisture that carrying soluble salts, the most significant are sulphates, nitrates and chlorides by a process loosely termed as “capilliarity.”

The height that dampness rises depends on several factors, including how porous the brick or stone is and the rate of evaporation. Masonry containing a high proportion of fine pores will allow the water to rise higher than a coarse pored material.
If rising damp is left large quantities of salts accumulate within the building structure forming a ‘salt band’. Both chlorides and nitrates are usually hygroscopic, (i.e. they absorb moisture from the surrounding environment) and, in general, the greater the amount of salts the greater the absorption of moisture – especially under humid conditions.

Damp proof course

What is a Damp Proof Course?

A damp proof course (DPC) – is a horizontal barrier used to protect buildings from moisture rising into interior areas. Over time the DPC starts to decay and also adaptations in the building occur, such as driveways and paths are raised that bridge DPC’s allowing dampness to enter the building fabric.

Why Rising Damp can be a Problem

Rising damp generally is not found when it originally occurs and this problem often leading to timber decay and causes heat loss due to the increased conductivity of the walls. It is unsightly, potentially unhealthy, and gradually decays the masonry causing the surface to break away. As the moisture enters plasterwork this leads to extensive and disruptive treatment internally for the owners.
Ideally should you suspect that your property is suffering from rising damp then the sooner you start thinking about treatment, the lower the cost and potential damage.

Rising damp

How to Spot Rising Damp

Typical indications of this damage can be wallpaper appearing blistered or beginning to peel, and discoloured patches becoming noticeable on lower parts of the interior wall. This type of damp can cause serious interior structural damage thanks to the deterioration of plaster work, the rusting away of skirting nails and the rotting away of skirting boards. Externally white bands of salts can be found to the lower region of the wall.

How to fix a Rising Damp Problem

Mostly it is to determine that you actually have rising damp as a large percentage of houses treated for rising damp did not actually have it in the first place – they actually had issues with other forms of dampness. Look externally to see if you have any faulty water services or a new patio or flower bed that has been placed higher than the DPC. Attending to any such items you could cure the damp problem by allowing the area to dry out naturally from opening windows and heating the room.
However, should there be no obvious signs, then we recommend instructing a surveyor to carry out a property survey where this will reveal the extent of any problem and any recommendations for the treatment required. For rising damp treatment this will involve the masonry being injected with water repellent chemicals and the removal and replacement of any affected plaster work and damaged timber.

We treat rising damp in Sheffield, Leeds, Barnsley, Rotherham, Manchester, Wakefield, Chesterfield, Mansfield to name but a few.

Lateral Damp

What Is Lateral Damp?

Penetrating damp (or lateral damp) is the horizontal ingress of moisture through the building walls. This can be either where external ground levels are higher than the inside ground level or where faulty render, weathered masonry (stone or brick), or faulty rainwater services (guttering or downpipes). This normally occurs on external walls and forms as isolated patches of dampness, which increase in size after periods of heavy rain.

Lateral damp can affect roofs, ceilings and walls and it can, unlike rising damp, happen at any level. Lateral damp is far more common in older properties, since they are more likely to have solid walls. A new build property with cavity walls offers much more protection and, as such, is unlikely to suffer from this type of defect. Though since the introduction of cavity wall insulation, this issue is starting to occur in newer buildings.

How to Identify Lateral Damp

Lateral damp can easily be recognised as a watermark generally appears on the walls or ceilings, drying a shade of brown. These damp patches will also grow if the water continues to enter the structure. Mould growth may occur with this form of damp, however, this will depend upon conditions. There may also be water droplets or free flowing water on the surface depending on the severity of the damp. However, there will be no salts present with this type of damp.

It can take a number of weeks or months before problems actually appear, so you must be vigilant when searching for signs and symptoms of penetrating damp or lateral damp penetration. You might notice:

  • Circles of damp on walls and ceilings that seem to get bigger.
  • Patches on the walls.
  • Crumbly, wet plaster.
  • Spores or mildew present.
  • Drips and puddles.

Lateral damp on wall

The Problem

Moisture enters the more vulnerable areas of a structure from a horizontal direction and then begins to descend deeper, breaking up materials like timber and plastering as it infiltrates further. This type of damp can appear at any level of a building and can create isolated areas of damp which can increase in size significantly after rainfall. Salt deposits can also be left behind once the moisture has dissolved, which may harm your building further if it is left to build-up.

Problems caused by Lateral Damp

Lateral Damp can lead to further problems, such as:

  • Wet rot
  • Mould
  • Damp plasterwork
  • Damp smells
  • Frost damage to masonry
  • Visible water damage
  • Rooms feeling cold and uninhabitable

Lateral damp on the outside of a house

The Cause Of Lateral Damp

This kind of damp problem can be caused by poorly maintained water and waste pipes which have begun to leak, damaged mortar joints, defective brickwork, disturbed tiling and guttering, insufficient damp prevention in wet areas and raised soil level.

The Solutions To Lateral Damp

With most damp problems the first step is to identify the area where moisture is entering the building, and stopping this occurring. Depending on the length of time that the moisture has been entering the structure, then plastering may be required and internal vertical damp proof systems employed.

Lateral damp on an inside wall

Rainwater Damage

As the heading suggests, this form of damp is associated with rainwater.  Rainwater damage is often noticed internally. Concentrated and prolonged wetting is likely to cause damp patches to the walls and ceilings, decay of timber skirting boards, panelling etc. If the problem is longstanding then when work starts or after a destructive survey will often reveal rot in concealed timbers, such as roof truss bearings beneath parapet gutters.

When raining, go outside to look at your water services, faulty joints, cascading water (sign of blocked guttering) become easily visible, allowing prevention works to take place.

The Problem

The appearance of damp becomes noticeable in living spaces within the property, often arriving from the upper parts of the building. This can cause plastering to disintegrate, making the interior walls crumble and appear dilapidated. Any timber used to construct the structure can begin to rot away and create an increased safety risk to anyone using the building.

Rainwater damage in a house

The Cause

Rainwater damage typically originates from defects on external areas of the property such as shoddy guttering, poorly pointed bricks, failing or inadequate damp proofing, gaps in rendering and overflows which aren’t draining correctly.

Due to water not being properly removed from guttering and running down the wall the external masonry can suffer from algae growth and eroded mortar joints. Brickwork and stonework can start to spall causing damage to the structure and wall ties. Render may fail locally, particularly inappropriate cement-based coverings that draw in water through hairline cracks. External joinery can be attacked by wet rot where there are leaks above doors and windows. Blocked gullies may lead to a build-up of water and damage to foundations.

Due to poor maintenance of gutters, downpipes and gullies that can become blocked if leaves, moss and debris (for example, broken tiles) are allowed to accumulate.

In addition wooden guttering if not painted regularly can start to rot and therefore allowing the rainwater not to be properly removed from the property.

Rainwater damage prevention


Good maintenance involves regularly clearing out rainwater fittings, particularly after the autumn leaf fall, and checking the system for defects.

Periodic redecoration of ironwork is required to inhibit corrosion or rot.

It can be advantageous to fit plastic leaf guards to gutters or wire balloons above downpipes. Leaf guards still admit pine needles and are sometimes easily dislodged, and material left to gather around wire balloons may cause blockages. Where visually acceptable, overflow pipes can be introduced above hopper heads.


Flood Damage

The flood water in your home or other property may contain sewage or other contaminants like petrol, diesel and other oily substances. Under normal circumstances this will be very diluted and present a low risk to human life, but we would recommend that a full decontamination is carried out. Then a drying process is carried out on the fabrication of the house and a structural survey to establish that the integrity of the building is still intact.

After a flood has occurred, many things need to be established prior to remedial works taking place. Firstly, what caused the flood? For example, the way in which you approach remedial works will be different depending on whether the flood was caused by a failed sewage system, or was due to a river overflowing. The possibility that the water may have come from more than one source will also need to be considered.


It should be quickly established if any contamination may have occurred, as this will strongly affect how the whole flood remediation process is handled. It should be noted that although flood water may not contain contaminants from its source, it may have picked up contaminating materials during the flood period. Possible sources of contamination include:

  • Black / Grey Water
  • Oil / Other Chemical Contamination
  • Sea Water
  • Biological (e.g. Sewage)
  • Silt, Salt, Sand / Other Fines

Flooding in a house

It is recommended that any materials affected by the flood are sanitised prior to removal.

Where buildings have been subjected to flood water above 0.6 m in height, or if there is evidence of movement or cracking of structural elements, a structural engineer should be consulted before any further works take place.

As a company we can guide you through each step of this process and how to rebuild not only your property but life after such an occurrence.

Flooding in a house

Worried about damp? Give us a call on 0800 859 5181