Victorian house with an internal leak stain.
- Test all bathrooms, toilets and sinks – ideally return.
- Use a monopole to view close up to a gutter.
An old leak and evidence of penetrating damp from gutters.
Signs of condensation such as from an unheated unvented utility room.
The house has been damp proofed against rising damp by injecting chemicals. Typically damp proofers replace ground floor internal plaster with an impermeable plaster, known as slurry. This increases condensation risk.
There is a damp patch in the master bedroom, immediately under the bath.
I have been informed by the vendor that there was a leak about a year ago, caused by cracked sealant cracked around the bath, and that it was repaired. The fact that this damp patch has been left unattended is a sign that the vendor hasn’t tried hiding damp issues.
I ran the bath and sink, and flushed the toilet, then tested the walls with a damp meter 24 hours later.
The wall was completely dry, so much so that paint is cracking off and easy to sand-down and repaint. I believe the vendor’s explanation stacks up and that there is no ongoing dampness. See use of Protimeters, here in conductance mode.
There is damp staining to the rear wall in the utility room.
Discolouration, like a tea bag stain is a sign that water is passing through brick or timber.
The Radio Frequency damp meter shows damp at depth.
I tested walls in radio frequency mode. Water reflects radio waves at a set frequency similar to mobile phone shields. Meters can’t differentiate moisture from other dense matter such as metal and concrete. They help trace damp in a normal, homogeneous wall. Readings below 300 REL indicate that a wall is dry below the surface, 999 REL is the limit.
I could not see the other side of the wall because it is covered in a form of trellising.
It is likely that the render has a crack in it and will therefore require filling. Note that the vent is blocked by the trellising, this means that humidity from the kitchen and generated by clothes washing is not being ventilated out of the utility area.
There is dampness on the utility wall rising in a triangular shape towards the cold external wall.
The profile of dampness is consistent with condensation. The heating has been turned off in the utility room, increasing the risk of condensation.
There is dampness to the front reception, which is open plan to the kitchen. Mould is growing by the corner.
Mould grows where relative humidity exceeds 85%RH for 6+ hours. Excessive humidity results from insufficient ventilation, poor air circulation and a cold surface. See surveyor.tips/mould. Mould is inhibited by nitrates found in groundwater. The presence of mould at the bottom of a wall eliminates rising damp as the root cause and points toward condensation from unvented excess vapour.
The wall was damp at the time of the survey.
There is some colour showing through, but this could be rust from the metal socket. Sockets are prone to dampness as a section of wall is cut out, a metal box installed and covered in absorbent plaster, which exacerbate the effects of condensation, see surveyor.tips/sockets.
A bit further to the left hand there is a patch of surface salts, but the wall was dry, albeit “at risk”.
There are calcium sulphate salts on the surface. Calcium sulphate is a key ingredient in cement and other building materials. If diluted in water salts tend to move to the surface. These can be removed with sandpaper and decorated.
The drain was functioning correctly outside however there are cracks which could cause rain to penetrate.
Rain could cause vapour to condense above the damp proof course, in the sub-floor resulting in localised “rising damp” like symptoms.
A hygrometer probe was left in the sub-floor void under the staircase, the relative humidity was normal.
If there was groundwater the cause of rising damp or active rot growth in the subfloor, then the humidity would have been above 85% RH.
I also looked in the subfloor for signs of rot. I could see no signs of rot.
There were signs of some of the timber has been replaced in the past this may well have been as a result of past rot.
I saw some woodworm holes in the subfloor section below the staircase.
Note the holes are oval, this is a sign that the timber was infested with woodworm before being sawn. As a rule of thumb, woodworm does not continue to remain active in sawn timber. You could compare this image to an image taken in a few years’ time to see if there is any activity and then spray the timber with readily available permethrin.
Note the line of holes in the wall above the subfloor void.
This is highly unusual and suggests overzealous damp-proofing treatment, despite the low risk of rising damp.
The kitchen has no externally ducted extractor fan.
Any vapour released from cooking will move around the open plan reception and into the utility room when the door is open.
There are some trickle vents in the property.
Many of the trickle vents were close at the time of the survey.
There is a high damp meter reading by the front door.
High damp meter readings by a front door is of very common, because this area of wall is vulnerable to heat loss causing condensation.
The damp meter reading dropped down to normal levels about 800 mil from the front door.
If there was rising damp, then the walls would be damp, in a more or less even line up the wall..
I left the datalogger in the front of the property for 24 hours, It did not show exceptional humidity.
The property is vacant therefore there is no vapour been generated other than from the penetrating damp to the from bedroom. The mould to the front and rust on the window box hinges demonstrates that there has been excess vapour in the past.
The rear toilet has a high don’t meter reading above the tiles.
In my opinion this is caused by condensation.
The top of the left-hand wall (when viewed from the road) was dry at the time of the survey.
It is possible that at some stage there was a blocked gutter or downpipe outside, a risk with any property, but if that was the case it is no longer damp.
There is a streak of dampness up the wall in the front bedroom.
It’s difficult to tell but it looks like it had been covered with a stain block at some stage.
The damp streak lines up with the socket. It is likely that a wire is imbedded in the wall.
In my opinion the metal from the embedded cable is causing heat loss and condensation. This side of wall was dry.
By contrast the right-hand corner is damp.
I spent some time investigating the right and corner from all angles. There was one likely root cause, a leaking gutter and a few contributory factors.
Looking under the gutter we can see a slight efflorescent streak on your side and dark and brick on both sides.
I looked on the neighbour’s side and the gutter appear to be clear but this could be a recent repair.
They have two cracked tiles but these do not appear to be major. I knocked on the neighbours door to ask if they have dampness themselves but unfortunately no one was at home.
As can be seen that are plants growing in the right-hand section of gutter.
The existence of plants suggest water is not draining away.
Under the gutter there is efflorescence, a sign that there is a leak from the stop end.
The stop end should be temporarily removed, a new rubber gasket fitted, stop end replaced and checked to ensure that it is not leaking.
There is a crack in the render immediately under the stop end, that should be raked out and repaired.
There is a possible crack between the coping stones which should be filled.
It is also possible that the flashing needs improvement, but I doubt it is the root cause of damp.
In the loft there is a line of damp staining on the ceiling.
It is possible that this comes from the roof, which has been repaired at different times. The staining is more likely to be a result of interstitial condensation forming within the loft void. Such stain may result from a leaking extractor fan ducting. It is possible that the ducting will need to be reinstalled. The easiest way to find out is to open up the vent and insert a humidity datalogger. There appears to be a vent out, this suggest any repair is likely to be relatively easy and involve sealing up ducting.
There is a crack in the window self to the front bay that should be wait out and filled.