Christmas 2020 saw my biggest survey to date, a Grade II 21 bed house and barn that I spend three full days surveying and many days report writing. Following the issue of the report, I provided cost advice to the client, who successfully negotiated a further six-figure reduction in the purchase price. The original C.17 farmhouse has had C. 18 and C.19 alterations and the external appearance of the house is now a mix of architectural styles. A good example of this is in the different styles of window in the front elevation.
I could spend all week writing about this house, however, that is probably excessive, and I will try and pick out a handful of points.
Stone – most of the property is built from Hollington Red, a Triassic Sandstone which is rather soft. As with most older properties I visit, re-pointing work and some ‘stone repairs’ had been undertaken in a sand and cement mortar mix, with what looks like the addition of some sort of polymer in places.
Cementitious mixes are inappropriate for use on traditionally constructed buildings and the external effects of this can be seen here. The cementitious mortar is placing additional moisture stress on the walls as they are unable to manage their moisture through the pointing (this should account for 70-80% of the moisture management). This is forcing the stone to manage the moisture as best it can, and accelerating its decay in the process. Some of the stone has also been bedded on its side causing it to lose its face. To address this, all of the sand and cement mortar needs to be removed by hand with a pluggin chisel and mallet or an Arbortech Allsaw, all of the joints need to be cleaned out and the friable surface of the stone cleaned up. The stones can then be repaired with a more appropriate product, likely a colour matched ST ONE in this case and the building can then be re-pointed in a non-hydraulic lime rich mix, preferably mixed hot on site. Listed Building Consent for this work would likely be a somewhat contentious point which I could write about for days.
Tree root damage – to the left-hand elevation, there was a substantial tree growing around two meters from the garage. The leaves from the tree were stopping any sunlight from getting to the garage roof and contributing to the heavy moss growth and also blocking the rainwater goods and drainage when they shed. Of more immediate concern was the root damage to the corner of the building. The movement was literally forcing the mortar out of the joints. Mature trees must be well managed for both their amenity value and to try to minimise the impact that their roots have on buildings that are close by.
Moisture – always be suspicious of strategically placed rugs. I lifted this one up to have a nosey and was straight away rewarded – someone had attached the floor with a blunt plane and added lots more screws to try to disguise the cupping of the floorboards. As this was pre-purchase, full investigations were limited, but a lifted floorboard revealed the early signs of decay due to the saturated air trapped under the boards. Relative humidity under the boards was 85%+.
Corroding ironmongery – another significant, but often overlooked problem with older buildings, particularly in agricultural ones is corroding ironworks. In this photo, we can see that a cast iron hinge pin has been set in molten lead in the stone block. Over the course of a few hundred years of exposure to the atmosphere, the iron has corroded. The corrosion has expanded the hinge pin and as there is nowhere to take up this expansion, it has shattered the stone. Further damage and rainwater ingress are now inevitable until the pin is removed and the stone is repaired. The stones in this photo are well-sized, I have seen corroding iron shatter stones the size of an adult torso before.
Cracked gully – virtuous clay drainage is brittle and needs to be protected when it is in situ. Cracked gullies are a common problem, this one had likely been cracked for many years and the ground all around was saturated and this had caused the fines in the earth to wash away. Unfortunately, this was one of two cracked gullies that were hard against the front elevation, subsequently leading to rainwater escaping all around the footings of the house. Left unattended, this will cause further soil erosion and eventually subsidence. The drains at the rear of the property were not much better, however, thankfully, the defective areas were further away from the base of the walls.
#buildingsurveyor #buildingsurveying #buildingsurvey #level3survey #charteredsurveyor #surveyor #surveying #estateagent #propertyrepairs #sustainability #surveylife #property #traditionalconstruction #construction #RICS #residential #house #buildingpathology #buildingdefects #conservation #restoration #heritage #historicbuildings #oldhouse #listedbuilding #damp #dampsurvey #condensation
Comments