Drones can make aerial inspection jobs a lot easier, quicker and safer and this case study will help to demonstrate how. The owners of a 1920s built country cottage have been experiencing water ingress via the chimney stack for around 2 years. So, how can a drone inspection help find a leak? Let’s find out.
The chimney stack comprises 4 flues; 2 that go to unused fireplaces in bedroom 1 and 2, 1 that goes to a log burner in the lounge and 1 that used to be connected to a multi-fuel range in the kitchen, which was removed some years ago.
So, what is the problem?
On days of heavy rain there is considerable pooling of water in the fireplace of bedroom 1 and slight dampness in bedroom 2. In the attic the external part of the chimney stack shows minimal signs of damp but is present. There is no sign of water entering the log burner which is positive but we cannot be sure of the same with the old range flue as this is now blocked up and behind a wall, so there is a chance this is damp as well.
The owners of the property do not have ladders long enough to reach the roof peak and do not have a roof hook to hold a third ladder stable enough to carry out an inspection. Having spoken to a contractor it was decided that a scaffold tower would be required to safely carry out the inspection in full and fixing points would need to be drilled into the walls to secure safety ropes. The owners have just re-rendered the cottage and were reluctant to damage any exterior of the property.
To carry out the inspection it was anticipated that it would take 2-3 hours to construct the tower and a further hour to make it safe and carry out the inspection. Two people were required to carry out the task which added additional cost.
It was decided that before work would commence, a drone inspection would be beneficial to survey the chimney stack and provide useful data which can be used in determining whether repair works would be needed or not, and the best way of approaching it.
Time for drone inspection
Having carried out a risk assessment of the local area including identifying any overhead cables, trees, and any other obstructions that could cause an accident, and subsequently checking any flight restrictions currently in place in the area, we were able to have the drone in the air in a relatively short amount of time.
When the drone was circling the chimney stack we were able to take multiple high-resolution images which we could analyse when back on the ground. The total flight time to capture all of the data we needed was around 10 minutes.
Here is a selection of images we were able to analyse.
What issues did the drone inspection identify?
We noted that the roof’s ridge tiles were slightly mossy but seemed undamaged and was unlikely to be the cause of the damp issues.
The flashing around the chimney stack, which is a common water ingress point, seemed in good shape.
The brickwork around the chimney stack itself is severely weathered and needs to be re-pointed in a number of places. Whilst this is important maintenance it is unlikely that the amount of the leakage the owners were experiencing was due to that.
It also seems that the working flue for the log burner has a cowl in place which prevents a lot of water ingress and one flue has been capped – we assume this leads to the old range but would need further investigation to confirm.
It soon became clear what the main issue was. The ‘flaunching’ (the mortar mix that fixes and seals the pots in place) is seriously cracked and in some places completely missing, as you can see above. You can see to the right of the flue, that there is a considerable sized hole. This would certainly be letting a lot of water in. This is a relatively easy fix; simply clear away all the old mortar and replace. Whilst up there it would be beneficial to carry out the pointing work as well.
In total the inspection job took around 1 hour to complete. 30 minutes to carry out the risk assessment, 10 minutes to carry out the inspection and a further 20 minutes to analyse the images and write the report. It did not put anybody at danger, did not require ropes or ladders or damage to the property and it provided solid evidence of the cause of the water ingress.
How can we help you?
Are you a residential or commercial property owner who would like a building inspection carried out using drone technology? Or perhaps you are a roofing contractor who wants to form a partnership to offer quicker and safer inspections, diagnostics and job estimating?
Either way, why not get in touch using the form below to see how Skyball Visuals can help.
Don’t forget, regular inspections like this can be a great way of spotting potential issues before they occur so don’t always wait for a problem to happen before acting.