FAQ's

If you have any questions and want some instant answers then take a look below at our most frequently asked questions in order to see if your issue can be resolved. If none of the FAQ's help to solve your issue then please use the contact form on the right to contact us or phone us on 0800 859 5181 and we will get in touch with you as soon as possible, thank you.

Our cellar is not very damp and has never flooded, so do I need expensive tanking systems?

The guidelines from British Standards that we work to states that ground water pressure will come to bear during sometime of the life of the building. Also making changes in the cellar could disturb the equilibrium of the ground so whilst once it was dry the removal of the cellar floor could result in the cellar having standing water due to polythene membranes blocking free passage of ground water.

In addtion whilst the walls may not be physically wet, they would be damp and therefore any timbers could become susceptible to timber rots.

So in short tanking systems are required.


Do your cellar conversions comply with building regulations?

This is a good question that I would hope more clients ask, and ask other contractors.

Waterproofing systems should comply with BS8102 British Standard for waterproofing structures below ground. In many instances the contractor only carries this aspect out (correclty you hope!), and does not then create a space that meets with building control regulations.  If you are creating a habitable space then there are strict guidlines that should be followed, often the cleint only realises that there is an issue when they either sell the property or when damp starts developing.  We submit the relevant documents to your local building control office with the design and specification for the proposed development – ensuring our clients that the work is done to a standard and certificates from building control are issued.


Damp is damaging the wallpaper.

“Our house has a small damp problem that is discolouring the wallpaper. What are the risks of leaving it untreated in short-medium term?”

The damp will continue to damage the wallpaper. Damp inside your property is unpleasant and can, in more serious cases, represent a possible health risk. You are best advised to get it dealt with before it gets any worse as the damp could cause additional damage to your home, are your ground floor timber? (dry rot could develop). In addition you should find out what type of damp the property is suffering from. A specialist survey is needed to determine the exact cause and any recommendations required. After all your home is possibly your single greatest asset.


Damp issues affecting wallpaper.

“I have a minor damp problem affecting the wallpaper etc. What are the risks of leaving it untreated in short-medium term?”

Apart from deteriorating your decorations, damp inside the home is unpleasant and can, in more serious cases, represent a possible health risk. Therefore it is advised to get it the problem looked at before it gets any worse. A survey is needed to determine the exact cause so the correct treatment can be conducted. The longer any possible damp issue could rise in the amount of work involved and costs will also increase.


How can I sort a problem with condensation?

Sadly there is no ‘quick fix’. Condensation in the home can be caused by a myriad of various factors, not least the occupancy lifestyle. Heating, air circulation and ventilation are the key issues. To areas such as the kitchen and bathroom extractor fans help remove moisture. Ventilation to the bedrooms can be installed to remove internal moisture or installing a positive pressure ventilation system that helps the entire house. This will circulate dry, relatively warm air quietly round the property and help to eliminate cold spots when condensation can form.


Rising damp caused by cavity wall insulation.

“Any quick/easy cure to stop rising damp caused by the cavity wall insulation bridging the DPC?”

Proprietary cavity wall insulation materials per se will not cause moisture to cross the cavity and so bridge a dpc. Therefore, if the insulation has been installed as a ‘retro-fill’, there should not be a problem caused by dampness coming through the insulation. However, should the cavity be filled with debris and mortar droppings then damp patches can occur. In new property isolated damp patches can be caused mortar happens to fall on the wall tie and then damp can present isolated dampness on internal walls. After a survey the property is suffering from rising damp then a remedial damp proof course installation will solve the problem.


My house has laminate floors.

“All my floors are covered with laminate floors, do they need to be lifted before any damp work takes place?”

Laminate flooring has been installed to property for many years. The main issue when laminate flooring is installed is from scratches. Providing that the flooring is adequately protected by the owners then this should not occur, we can provide the service of covering the flooring at an additional charge.


Are there any grants available for damp proof courses?

“I have damp problems to my property and I was wondering if there are any grants available to cover the work?”

You need to contact your Local Authority regarding grant availability as this will vary from area to area.


Damp to my old terrace house.

“My terraced house is over 100 yrs old. I have damp on the party wall, how can this wall be damp and can it be treated?”

Dampness can create problems to any wall within the property, there are many forms of dampness and by having a survey it will be able to diagnose the source of the dampness – rising damp and salt damp (from neighbouring fireplaces) could be the cause.


Do you have to leave the wall to dry out before putting new plaster on?

“I have had work done on my damp problem where the contractor replaced the plaster straight away and did not allow for the bricks to dry out before putting the new plaster on, Should bricks have dried out before adding new plaster?”

Specification of the plaster is the key to re-plastering after the installation of a remedial dpc. The brickwork will be damp and will need to dry out, though it is more important to consider salts that have been deposited due to the rising damp. These salts (chlorides and nitrates) can absorb and release moisture and cause the wall to stay damp by crystallisation. A standard lightweight plaster is not suitable for this situation – specialist plasters, tanking membranes or sand and cement render with a salt retardant additive must be used to counteract the salt contamination in the masonry and stop it migrating to the surface.


I have mould growing in the corner of my lounge.

“I have a damp mould problem in one corner of my living room. How can this be fixed ?”

Initially this damp problem sounds to be due to condensation. Mould forms on walls due to a cold spot and in corners the air doesn’t move freely around and therefore allows mould to form. As a ‘quick fix’ by wiping the area with a fungicidal solution, though it will simply reappear as the cause is not yet dealt with. One of our surveyors will carry out tests and provide reports on the causes and the remedies recommended to stop this problems continuing.


The brickwork below the damp proof course is crumbling is this rising damp?

“Below my damp proof course the bricks are starting to crumble. Is this likely to be caused by rising damp?”

Dampness does absorb into the brickwork and over time can cause the bricks to start to crumble. Whilst this is a concern the real concern if the dampness has broken through the damp proof course itself as this would cause other issues.
The crumbling of the brick is due to salt, when the months are colder the moisture within the bricks expand due to frost. When the moisture freezers it causes the bricks to fracture and then the faces of the bricks start to come away.


Using a membrane can I place that directly on the wall so I do not need to remove the plaster?

“I am considering to put a cavity drainage membrane directly onto existing internal plaster to save me hacking off all internal plaster and re plastering with salt inhibitor/cement base.”

Using a membrane you can install it directly onto the existing plaster to avoid having to put any specialist plastering and to use a standard lightweight plaster. Using this method will affect the thickness of the wall and in turn alter all the wall profiles in terms of architrave and perhaps pipework. Also should the plaster in time behind the membrane start to fall away then there is a strong possibility that this will affect the membrane and new plaster.


The outer brickwork has white salts to the base of the wall that looks unsightly, how can I stop this?

“We have white salts on the external brickwork and it looks awful how can we stop this?”

Sadly in this instance there is no treatment that will work effectively without drastic action such as rendering. In this instance we would recommend simply brushing the area free of salts when required. There are solutions that can be applied though these do not last for any significant length of time.


Walls are wet to the touch.

“We have found that certain walls are damp to touch at night and dry in the morning, wall paper has started to peel off, any advice?”

Condensation firstly springs to mind especially if the walls in question are outer walls. Should these walls be inner walls then plaster containing high levels of salts that has got there from damp relating problems such as rising damp. The reason why it appears to be damp in the night is that the house will be occupied and therefore increasing the humidity levels where the air becomes stagnant, in the morning the air moves and becomes dryer. If condensation is the issue then measures such as positive negative systems are employed or fans, if plaster is at fault then removing the plaster and dealing with any potential damp issue is needed.


What is causing my skirting boards to crack?

“I have noticed that my skirting board is starting to crack is this caused by damp? Dampness does effect timber and as a result of a rot infection can cause the timber to crack. Is there dampness that you can see to the wall above the skirting board?”

Our surveyors will examine the area to detect any areas of moisture to the wall and take moisture readings of the timber also – looking at the timber for signs of fungal attack. It is advisable for a survey to be carried out to determine the cause of the cracking before a potential fungal attack really develops.


How can I check that there is no fault with the damp proof course or plaster?

“A dpc course was carried out in 2006, plaster was removed though I have started to see mould appearing to those walls. How can I check that it is not the dpc at fault or plaster?”

You should contact the original contractor who carried out the work to come back to inspect it. Should the company not wish to carry out a further inspection then you are within your rights to obtain another report and claim against the original contractor to rectify the fault. Tests with the moisture meter and more destructive tests can be taken to see if there is a fault with the dpc or plaster.


The outer wall beneath the floorboards is damp, what is the cause is it penetrating damp?

“I have damp under the floorboards by the outer wall could this be penetrating damp due to the recent wet weather and what can be done?”

Sadly without inspecting the property in greater detail it is rather difficult to be able to provide any significant advice. There could be many aspects that has caused the damp, a leaking pipe; the presence of any high ground level outside; the history of any flooding; other building defects that may be contributing to the dampness. The cause and the solution will be provided after a survey has been conducted.


Rising damp caused by cavity wall insulation.

“Any quick/easy cure to stop rising damp caused by the cavity wall insulation bridging the DPC?”

Proprietary cavity wall insulation materials per se will not cause moisture to cross the cavity and so bridge a dpc. Therefore, if the insulation has been installed as a ‘retro-fill’, there should not be a problem caused by dampness coming through the insulation. However, should the cavity be filled with debris and mortar droppings then damp patches can occur. In new property isolated damp patches can be caused mortar happens to fall on the wall tie and then damp can present isolated dampness on internal walls. After a survey the property is suffering from rising damp then a remedial damp proof course installation will solve the problem.


I have drill holes around my property and presume this to be the damp course. But I still have areas of dampness inside at the foot of the walls. Can you explain this?

There could be a number of reasons for continuing dampness –depends what and where the dampness is – failure of the injected DPC or incorrect installation, continuing bridging of the DPC. However the most common fault is in the plastering either because a lightweight plaster has been used instead of a sand and cement render or where the new plaster has not been stopped short of the floor and so is bridging the new DPC.


Why do I have to have the plaster removed when you install a new damp proof course? The plaster is solid.

If the wall is damp as a result of the rising damp, ground salts such as chlorides and nitrates enter into the brick and plaster. These are hygroscopic which means that they can absorb moisture from the atmosphere so in cases of high humidity there is continuing internal wall dampness. Removing the contaminated plaster it removes the salts and the inability to interact with the atmosphere, leaving the plaster the wall surface will still be damp.


We had a DPC course done in 2003, the plaster was replaced but mould has now started to come back through how do I make sure this is a fault in the DPC and not a fault with the re-plastering?

Contact the contractor who installed the work in the first instance for a re-inspection. A surveyor should be able to diagnose the source of the problem and if the installation is shown to be deficient, then you should be able to make a claim under the guarantee terms. We find that the most common fault is the re-plastering and for the wall to continue to be damp. Should the original contractor not call out to the property feel free to contact us where we will survey the property.


My property was damp proofed in the past but I still have areas of damp. Can you explain this?

On this issue there could be a number of reasons – often the system was only injected to the outside walls, was only a partial dpc , not installed properly or the plaster was not removed or incorrect plaster used. Do you have any guarantees and plans for the work carried out to your property? In order to establish the cause of the damp we will need to provide a survey.


Why does the plaster have to be removed when you install a new damp proof course? Other companies say that you can just inject a dpc and the plaster will then dry out.

When rising damp enters the structure it contains chlorides and nitrates. These are hygroscopic which means that they can absorb moisture from the atmosphere; therefore the wall still remains damp. Removing the plaster will isolate the salts to stop them interacting with the environment Companies that say there is no need to remove plaster saying that it will dry out are not following specific guidelines set out by British Standards and therefore we would question if they will correctly install a working system.


We have a dpc installed by another company and it has failed, will you survey it?

“Our damp proof course has failed and we want you to survey the property to tell us if it has failed.”

We would recommend that you contact the original contractor and ask them to call out to the property to carry out an assessment on the dpc. If the contractor cannot be found, gone out of business try and see if there is any insurance on the work that they carried out. Sadly if there is no insurance on the work then we will happily call out to the property though will survey the property as if no treatment had taken place. We will provide a report and recommendations on the course of action needed.


We have a damp mould in our daughter’s bedroom please help.

“We have mould in one of the bedrooms, please help.”

We presume that this a bedroom located to the first floor and if so sounds like a condensation problem. Is the mould forming on the outside wall as the outside walls are colder than the internal wall and therefore can allow air to condense on it – creating mould. Using an anti-fungal solution to the wall can help remove it though will not stop the mould from coming back, and mould can be harmful. We are happy to carry out a survey to provide more help and advice.


How long does a survey take?

Most surveys take around 30 – 40 minutes but this can depend on several factors such as the type of survey, where the survey is to be conducted (room or entire house)


How do I arrange for Cannon to carry out a survey inspection?

Please contact us for more help.


Can you tell me over the phone how much the work is likely to cost?

Unfortunately not, as all properties and their problems can be different so an individual survey of your property would be needed to establish the full extent of any problem and in order to recommend any treatments.


Are you members of any organisations?

Yes we are proudly associated to the following trade associations. We are vetted and audited prior to gaining membership.

  • Federation of Master Builders where only those builders and specialists who can prove their skills and good business standing are accepted as members. FMB builders work to a strict code of practice which they commit to every year when they renew their membership.

 

  • TrustMark is a Government backed initiative to help consumers find reliable and trustworthy builders and specialist tradespeople to carry out repairs, inside and outside the home. All FMB members are eligible to join the scheme.

 

  • ISO 9001 is the internationally recognised standard for the quality management of businesses.

What does a survey involve?

Our staff will try and gain as much information prior to any visit, when contacting us about any potential survey please consider any items that are important i.e. such as access, restrictions etc.  We carry out a myriad of surveys and use different apparatus for different surveys.  The length of the survey depends on the type of survey and the areas involved, typically a survey could take from 20 minutes to a few hours, so please allocate enough time for the survey.

Wherever possible every effort is made not to disturb the property and at this stage there should not be any undue mess. Fitted carpets will a floor timber survey, only being lifted if essential. Likewise in the case of timber floors it may be necessary to lift some floorboards in order to examine the sub-floor area. (though our surveyors do not carry any cutting tools and will only lift inspections boards already been lifted – should there not be any inspection boards then a charge and another visit will be required)  Even if sections of floorboards are raised a full picture of any issues or extent may not be truly revealed until the commencement of the remedial work.  The surveyor will advise you if this is the case.


If we have a survey done, how long is the quote valid for and how long have I got before I have to have the work done.

Our quotes are valid for 2 months from the date of issue.

Should there not be any significant charges to the building then generally the surveys will last for at least 6 months. However, there is one exception in the case of a dry rot outbreak where any extended delay could result in further damage. The surveyor’s report would make clear the severity of the problem and the urgency of repair.

Though we must stress that any issues found within the survey if left could only increase the disruption of work required and cost if left for a period of time.


Do you charge for carrying out a survey?

This depends on the circumstances, i.e. if you are looking to buy the property, the nature of the problem, whether a written report is needed etc. We would normally charge on pre-purchase surveys and for wall tie inspections or timber surveys where we have to access sub-floor areas (not cellars) to inspect timbers. However, the survey fees are discounted should you accepted any of our recommendations.


Can I live in my property while treatment is being carried out?

Generally yes, although this depends on the nature of the work involved. With any type of construction work it involves a degree of disruption and mess. We aim for as minimum disruption as possible and will consult prior to any work commencing and issue advise.


How much does a damp proof course cost?

This is one of the most common questions asked. This all depends on the amount of treatment required and what treatments are to be carried out.
Guidelines can be given though these should not be taken literally, we have heard of certain companies giving prices of damp proof course injections over the telephone, though we would air any client on the side of caution in accepting any type of offer as it may not need that type of treatment. Did you know that it is reported that 75% of damp proof course injections did not need doing. Therefore it is why a specialist survey is necessary to discover any issues and a report and estimate is provided. With regard to a survey fee please contact our office as most are free though there is a charge for some.


Can you tell me over the phone how much the work is likely to cost?

Unfortunately not, as all properties and their problems can be different so an individual survey of your property would be needed to establish the full extent of any problem and in order to recommend any treatments.


Is the work guaranteed?

Yes all our work is covered by a company warranty valid up to a maximum of 20 years depending on the treatment undertaken. Insurance Guarantee is also available, though a charge is applicable.


What happens to my guarantee if I sell my home?

The guarantee is on the treated areas of your property and can be transferred to the new owner of your property. You can contact our office for more details.


Are your guarantees insurance backed? What happens if I want to make a claim and your business is no longer trading?

Business is no longer trading? All our work is covered by a company warranty (length of warranty dependent on nature of work) We also offer additional insurance backed guarantees from Insured Guarantees, Federation of Master Builders (FMB) and TrustMark so in the event that Cannon Contracting Ltd go out of business, an independent contractor would be appointed to honour any claims under the terms of the guarantee. Ask our office for details and premiums.


Woodworm treatment.

Do I have to move out when your men are spraying the property for woodworm?

Years ago the industry used high solvent based high odour chemicals that resulted in the areas being treated having to be vacated for 48 hours.

We use water based low odour micro-emulsions that result in the room being reoccupied after only 1 hour.  All our chemicals are fit for purpose and are accredited by the Health & Safety Executive (HSE).


I have holes in the timbers in my loft.

“Whilst putting things into the loft I have found holes to some of the roof timbers, is it woodworm and how can you tell if they are active ?”

How long have you owned the property? When you bought it did you have any guarantees or evidence of past treatments to this area? The timbers really need to be surveyed. It possibly could be a wood boring insect though it may be historic and not active. You can be assured that we will never recommend any treatment that is unnecessary.