Endorsed by Which?

JPM Independent Surveyors


65 Reviews

Opening Hours
Today - 08:00–18:00
  • Monday 08:00–18:00
  • Tuesday 08:00–18:00
  • Wednesday 08:00–18:00
  • Thursday 08:00–18:00
  • Friday 08:00–18:00
  • Saturday 08:00–18:00
  • Sunday 08:00–18:00

What is a Which? Trusted Traders Islington Trading Standards Approved Endorsement?

Which? Trusted Traders has partnered with Islington Trading Standards to create an Islington Trading Standards Approved endorsement. In addition to our standard trading standards assessment, this trader has had a DBS check and is subject to a Trading Standards intelligence check.


I provide specialist damp investigation reports and timber reports with solutions to fix the problems. I also offer Spayed foam evaluation reports.

Dampness is often misdiagnosed by contractors.
Quite often the correct solution is simple and inexpensive.


I am not a contractor, I am a surveyor. I do not carry out remedial damp proofing or building works so you can rest assured that my reports are competently impartial.

Experienced qualified independent damp and timber surveyor.
: Dampness
: Condensation
: Mould
: Timber decay
: Woodworm
: Ventilation
: Spayed foam evaluation.

CSRT Qualified.
Property Care Association.
Expert Witness Institute.

20+ years experience, fully insured, I provide for home owners, tenants, estate agents, landlords, architects and property pre-purchase.

Covering areas of North London, East London and West Essex.

What we do

  • Damp proofing and timber preservation services

    • Condensation and humidification control
    • Timber treatment services
    • Woodworm treatment
    • Injection damp courses
  • Mould

    • Mould investigation
    • Mould survey
  • Surveyors

    • Building Surveyors
    • Damp proofing surveyors
  • Builders

  • Specialised building trade contractors

  • More Services

    • independent
    • timber
    • rot
    • water damage

Customer reviews

Why you can trust these reviews

All reviews are verified as being genuine and a true customer of this trader.

How can we be so sure?

100% of the reviews we publish have been through our stringent moderation process.

65 reviews
Customer Service
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Independent, professional, fast
Customer Service
My partner and I hired Jason for a damp survey on a house we're buying. Jason provided a thorough report on the same afternoon as his inspection, with easy-to-understand practical tips on how to mitigate any problems. We had a few follow-up questions on the report, which he answered promptly. Jason is keen to stress his independence - he's not tied to any damp-proofing firm, so he has no interest in selling any unnecessary products or damp-proofing. All in all, we'd recommend him for anyone looking for a professional, fast and non-invasive damp survey.
Customer in Greater London Posted on 09/11/2021 , work completed 02/11/2021
Comprehensive and thorough survey
Customer Service
We were very impressed by Jason's work. It was easy to arrange a visit, the date and time were kept to, the survey itself was extensive and Jason answered all of my questions with enough detail to make it clear what our options were without drowning in jargon. The report was produced quickly and was comprehensive, giving us a clear steer on the remedial work needed and which areas were of most importance.
Customer in Greater London Posted on 01/11/2021 , work completed 21/10/2021
Excellent pre-purchase damp survey
Customer Service
We were buying a Grade II listed Victorian house and were initially concerned about getting a pre-purchase damp survey as there are so many bad reports of operators in the industry. Of the people we contacted Jason stood out for his responsiveness and helpfulness, the survey was arranged and the report turned around quickly, it was clear and detailed with cost estimates for the work and extremely helpful recommendations. The price was also reasonable. We were very impressed and would highly recommend Jason to others.
Karl and Hannah in Greater London Posted on 12/09/2021 , work completed 11/09/2021
Efficient and thorough
Customer Service
Jason arrived on time and carried out a thorough investigation of the flat. He was friendly and explained some of the issues we had been concerned about while carrying out the survey. He supplied the full report on the same day and for such a great service, charged much less than we had been quoted by competitors.
Evie in Greater London Posted on 03/09/2021 , work completed 02/08/2021
Prompt and efficient attention
Customer Service
I required a building survey to be carried out on inadequate work done by a roofing contractor. I contacted Jason Mahoney on the recommendation of Which Trusted Traders. He replied promptly, fixed a date and provided me with a full scope of the proposed survey. On the day he arrived promptly, undertook a very thorough survey and a full and very detailed report with a comprehensive list of recommendations was provided the following morning. I can thoroughly recommend his services.
Eric in Greater London Posted on 18/07/2021 , work completed 18/07/2021
Brilliant service, fast report, thorough survey. Would highly recommend.
Customer Service
Jason was highly responsive and professional from our first contact, and liaised with our estate agent to enter the property. Despite being very busy at the moment, Jason performed the survey in a very short time frame for us and returned the report on the day of the survey. The report is thorough, and the advice was clear and reasonable. I would highly recommend Jason and couldn't have expected any better service.
Harvey in Oxfordshire Posted on 16/07/2021 , work completed 10/07/2021
Independent damp survey-- excellent service
Customer Service
Jason Mahoney responded very quickly to my request for an independent survey and delivered his report and recommendations within 24 hours of the survey. He provided a clear and comprehensive report with useful recommendations to address the dampness in my flat. I was impressed with his detailed explanations of the causes of the damp problems and how he considered the options for dealing with the problems carefully. His independence from commercial vested interests was invaluable in helping me to make balanced decisions about the best way forward.
Customer in Greater London Posted on 05/07/2021 , work completed 03/07/2021
Instrusive Damp Survey
Customer Service
Jason carried out an intrusive damp survey. He responded quickly to the request to do it, and carried it out efficiently. He was happy to explain what he was doing along the way. He produced the report in a couple of days, and it was very clear and well explained. He seems to be very well informed about this area, and we are grateful for his help.
Ed in Somerset Posted on 29/06/2021 , work completed 15/06/2021
Exceptional, reliable and thorough
Customer Service
I contacted Jason last minute as we were against the clock to get a damp and timber report for our mortgage offer (the condition appeared in the offer paperwork and we had to complete within days). Jason really went above and beyond. He luckily had a cancellation the next morning. Jason inspected the property, and provided a thorough and flawless report with full costings (and lots of helpful additional information) before the end of the day. He really saved the day and we can’t thank him enough. In addition to allowing us to meet the deadline- the report he provided gives us the confidence that we understand the damp issues (very old property), and the work involved before we purchase. Truly exceptional- thank you!!
Customer in Greater London Posted on 22/06/2021 , work completed 21/06/2021
Great work
Customer Service
Jason surveyed a property we wanted to buy after damp issues were raised. His report was returned to us the same day as his inspection, but was completely comprehensive and also really easy for someone who has no experience of reading technical reports to understand. His professionalism was such that even though his report led to us negotiating a big price reduction on the property, the vendors told us that Jason was a great guy and that they were really impressed by his work. Can't recommend him enough.
Customer in Greater London Posted on 12/06/2021 , work completed 15/05/2021