Black Mould On Walls

Its that time of year folks, condensation black mould is back in the North East, this particular photo was taken from a recent job the team carried out in Durham, It’s a Durham University student property that had this area of wall damp proofed roughly 4 years ago, the contractor used a sand and cement render system to damp proof the wall.

This method of damp proofing isn’t used as much these days for various reasons, the main reason being that the dense mix of sand and cement results in a cold surface, you might be thinking what’s that got to do with anything? Well, the cold surface of the wall drops down below dew point quicker than the other surfaces that might have warmer materials applied to the wall surface like plasterboard or browning/plaster finishes. Because of the cold surface, condensation is more likely to form, this then leads to black mould spores appearing on the surface, once the black mould has taken hold they will constantly be ‘watered’ by the high levels of humidity that are present in ‘well lived in’ student houses, we see this regularly with student houses in Durham, Newcastle and Sunderland.

If you’ve got black mould issues like this affecting your property in the North East, please give us a call on 01914159471 and we’ll pop round and check it out, condensation in the North East is a very common problem.

Woodworm found on recent survey in Durham, clients asked us to carry out a survey prior to purchasing their new house. The woodworm infestation was that bad the floorboards simply collapsed when stood on. Woodworm was also found in other areas, believe it or not but this was missed by the RICS surveyor who valued the house, luckily we picked the infestation up prior to our clients exchanging contracts which allowed them to renegotiate the purchase price to take into consideration remedial works to treat woodworm. Just goes to show how important it can be to carry out a woodworm survey when purchasing an older property.

Prior to carrying out a recent pre-purchase survey at a house in Durham I was informed by the potential purchasers that areas of mould were present in the living room and they wanted to get it checked out prior to exchanging on the property. I had a lengthy discussion with them over the phone before actually booking the appointment as their description (mould in living room) appeared to suggest that the property was suffering from black mould which is a symptom of condensation, this can usually be dealt with successfully by increasing ventilation.

They insisted that they wanted the peace of mind in carrying out a pre-purchase survey and we’re happy to press ahead. The property in question was a large detached stone built house under a slate roof, the estate agent informed me that the property was a deceased estate and hadn’t been lived in for over 18 months.

As soon as I opened the front door I was hit by a pungent mushroom type smell this arose my suspicions immediately. As soon as I walked into the living room I was met with one of the largest ‘Dry Rot’ outbreaks I have seen for some time, as you can see from the pictures the Dry Rot fruiting bodies have infected the wall, curtain pole and ruined a picture hanging on the wall, this Dry Rot outbreak had been happening for some time, the cause of the outbreak was from a pe leaking in the bathroom above.

The cost to rectify this damage would have been several thousand pounds, following my report the purchasers decided not to proceed with the purchase as the vendors wouldn’t move on price, whilst they were obviously disappointed, by having the survey carried out this saved them thousands of pounds in the long run on what they initially thought was just a bit of mould.

We have recently been surveying some older stone built properties for Allendale Estates (Lord Allendale), certain properties have been suffering with ongoing damp issues for a number of years. The properties are typical of rural Northumberland, stone built under a slate roof with cast iron rain water systems, the properties are of a considerable age and at one time would have been heated via solid fuel fires situated in the stone inglenook fireplaces. The properties originally had single glazed timber sash windows and doors, some of which are still in place to this day.

The damp areas we were asked to look at were not your typical everyday damp issues, several areas of dampness were noted up to 2m high with spots of high moisture readings all over the walls in various areas. We agreed that we would need to remove the wall plaster in certain areas to determine what was going on behind these damp patches.

Once the skim coat/ surface plaster was removed we discovered an old remedial damp proofing system had been fitted in the past, a sand and cement render had been applied up to a height of 2m high throughout the ground floors, it was up to 2-3inches thick in places. This was not allowing the walls to breath properly and also providing a cold surface for condensation to form throughout the winter months.

Old stone built properties need to be treated with respect, they do not take too well to modern building techniques, we have recommended a lime based render to be installed once the sand and cement have been removed, this will allow the walls to dry down over time and allow them to ‘breathe’. The inglenook fireplaces will also be opened up which will help with ventilation and reduce the build up of condensation throughout the winter months.

Wall Ties……what are they and why do they often crop up when buying or selling a house!

Wall ties are used in the construction of cavity walls, their purpose is to tie the internal and external walls (or leafs) constructed of bricks or blocks together. Wall Ties are placed in the cavity wall during construction and span the cavity. The ends of the tie are designed to sit in the mortar beds between the brick/blockwork and form a structural bond once the cement has dried.

Wall ties come in all shapes and sizes, a common feature built into the design of the tie is means of preventing water transfer from the outer to the inner leafs. In flat ties this can be a twist. In wire ties this can be corrugations formed in the wire or again a twist.

 

The problem associated with wall ties is commonly referred to as Wall Tie Failure, wall ties are exposed to water and chemical attack from cement used in the construction of walls. In the north east a common type of mortar widely used in the past is referred to as black ash mortar, this type of mortar is known to have a corrosive effect on wall ties. Wall ties were traditionally made of galvanized steel, the fishtale tie being the most common. In the mid-twentieth century wire ties were widely used, again made from galvanised steel wire. As time has passed many galvanised steel ties have deteriorated due to moisture in the outer leaf  of brickwork.

 

The corrosion may force apart the cement joints and even result in the collapse of walls if no remedial action is taken. Any cracks appearing in cavity walls dating from the twentieth century need to be investigated before irremediable damage ensues. Horizontal cracking is especially suspect. Failed ties have to be isolated and substitute specialist ties installed by drilling through inner and outer leaves from outside the building. The replacement ties may be fixed mechanically or with special adhesive resins.

Galvanised steel ties are no longer in use for this reason. For a brief period, plastic ties were used but were not satisfactory. Modern practice is to use stainless steel ties.

House Surveys & Wall Ties

Surveyors carrying out inspections in relation to house purchases will often recommend a ‘Cavity Wall Tie Survey’ is carried out prior to approving the mortgage, this is usually due to the age of the property rather than tell tale signs, surveyors tend to err on the side of caution regarding wall ties, its not uncommon for surveys to be carried out and the wall ties are fine.

We have many specialist surveying tools at our disposal when carrying out wall tie surveys to determine their condition, but the best and most trusted method is to physically remove a brick which allows you to see the part of the wall tie that is hidden as it sits in the outer leaf, its not uncommon to look inside the cavity and the exposed part of the wall tie appears fine with little or no sigs of corrosion, then when you remove the brick and expose the part of the wall tie that was embedded in the outer leaf and it has advanced stages of corrosion.

All wall tie surveys carried out by us involve the removal of bricks and a thorough inspection can then be carried out, when instructing a company to carry out a wall tie survey in the north east ask them if they provide you with photographic evidence of the wall ties, if not stay away……..we always without exception include photographs of the exposed wall ties for your peace of mind.

Call us on 0191 4159471 if you require further advice or to request a wall tie survey!

Dreaded Dry Rot

We were recently instructed by a private bank based in Cardiff to carry out a survey on a property they own in Wrekenton, Gateshead, The property is currently for sale with a local estate agent in Low Fell, Gateshead following the passing of their equity release client. The estate agent had informed them of some mould type stuff growing in the garage area close to the door which looked ‘nasty’. We arranged a date for me to pick the keys up from the estate agent and carry out a survey.

Early Tuesday morning I called down to Low Fell to pick the keys up from the estate agents then I headed back up to Wrekenton, Gateshead to survey the property. I’m not sure how other surveyors feel but I always feel a little bit hesitant when visiting an empty property, I’m not sure exactly why but there’s something a bit strange about putting the key in a door to a house you’ve never set foot in before and not knowing what to expect, I often find myself shouting…hello….hello is there anyone in, nobody has answered back yet and ive no idea what I would do if they did…probably run a mile ha!

Anyway, back to business, following instructions from my client I checked out the internal bay window area in the living room, nothing was obvious apart from a distinct lump in the concrete floor in the living room near to the bay window, I then went outside into the garage area and this is where the problem became more evident, the wooden supporting post surrounding the garage door had an outbreak of Dry Rot growing nearly full height, the Dry Rot had also grew alongside brickwork near to the wood strut, at the base of this wall was several pipes than ran from the combination boiler which was situated in the garage, these pipes (due to them being in an unheated garage) had foam lagging round them and the Dry Rot had grown round the lagging with a large fruiting body present.

 

 

 

 

 

 

 

 

When investigating Dry Rot outbreaks the job of the surveyor is to determine what caused the Dry Rot in the first place, Dry Rot is usually associated with a leak from somewhere, this could be a leaking gutter, washing machine leak or water pipe, in this particular case it was easy to determine the exact cause of the Dry Rot. Where the central heating pipes returned through the garage wall into the living room a defective fitting ‘copper elbow’ was leaking and had been for some time, left unattended this had spread significantly over a that period of time.

The central heating pipes where they enter the living room have been chased into the concrete floor, they ran to a radiator in the bay window area, the Dry Rot had spread along these chases and into the living room floor eventually reaching the skirting boards, as you can see from the pictures below its scary just how aggressive this Dry Rot fungus can be, it had literally grown through the concrete floor and found its next victim. For more information regarding Dry Rot please visit https://dampandtimbersurveynortheast.co.uk/timber-survey/

We’ve been kept busy lately with the daily enquiries from clients complaining of damp patches of black mould appearing on walls within their properties.

What is black mould?

Black mould is a problem associated with condensation – an extremely common problem in properties between the months of October to March. We refer to this as the ‘condensation season’. As soon as the temperatures drop outside, external walls cool down and water vapour inside the property condenses against cold internal surfaces, providing the perfect conditions for black mould to grow. Black mould spores are present in the atmosphere at all times and when conditions are right, they will form and then rapidly multiply.

Why do I get condensation in my home?

Condensation is more prevalent now due to modern building techniques.  Houses are effectively sealed too well, double glazing being the number one culprit, and the moisture in the air from cooking, bathing, drying clothes and such like has nowhere to escape.  In days gone-by, when most properties had open fireplaces and single timber glazing, condensation was never a problem as properties naturally ventilated themselves.

Get in touch

If you have black mould condensation problems in your property and would like some specific advice please feel free to contact us on 0191 415 9471 and we’d be happy to help