Building Preservation

MacLennan's surveyors are qualified by the Institute of Wood Science as certified surveyors of timber treatments. We specialise in the sympathetic damp proofing of historic buildings, using techniques devised over the last 30 years.

MacLennan carry out full timber and structural surveys, and provide detailed reports for defects and where necessary, a full specification and premedial work program.

We provide a lasting cure to the problems with damp that are found using salt and plaster analysis, Carbide meter testing and, where necessary, laboratory testing of the building fabric.

It's likely you will find damp in an old English building as they are often built using breathable materials and friable substrates. A lot of damp proofing contractors will turn up, test with a damp meter and tell you to inject chemicals into the base of the building, but these methods won't work for this type of construction.

Sympathetic damp proofing can preserve the breathing quality of a structure while keeping the inside dry.

damp proofing united reform church

MacLennan are one of the few companies to give underwritten guarantees for work carried out. All our staff attend regular training courses covering our services. as well as Health & Safety training. The Managing Director is IOSH (Institute of Safety & Health) accredited and encourages a health and safety conscious ethos throughout the company. The company is CHAS and Safe Contractor accredited.

Traditional & Historic Buildings

Traditional & Historic Buildings
Preserving historic buildings in the UK

Timber Repairs

Timber Repairs
Repairing rotting timber or strengthening for greater loads

Helical Repairs

Helical Repairs
Structural repairs for all buildings

Get in touch with our technical team today!

Maclennan have been experts in designing, installing and guaranteeing systems for over 30 years.

Preserving buildings for years to come

MacLennan have experience with a range of methods for dealing with the cause and effects of damp in old historic buildings.

We often recommend a damp proof cavity membrane system. This works by preserving the structure and allowing it to breathe naturally while keeping the inside of the building dry and comfortable for the occupants.

We offer guarantees on these systems because they work and last. Methods reccomended by surveyors without experience in working on old buildings won't work here.

Cavity Drain Systems

Lime plaster

Lime plaster is commonly used for damp proofing hwoever this should be carefully considered as it may not be best the best solution long-term. Read out technical guide for the Do's and Don'ts of Lime Plaster and Damp Proofing.

Damp Proofing Cavity Membrane

Why should I work with MacLennan?


We Design, supply and install. There's no split responsibility with MacLennan.


MacLennan live and breathe waterproofing, have a look at one of our free CPD seminars and find out!


MacLennan has the most comprehensive guarantees and insurances in the industry.

What are common causes of damp in old buildings?

Trapped Moisture

Using modern acrylic paints or water repellent coatings on old masonry walls can lead to damp problems elsewhere as the walls cannot breathe.


Using hot water produces steam/vapour that needs to escape. Ventillation is extremely important in old buildings that weren't built to be airtight.


A leaky roof/chimney/parapet can easily translate to a damp patch on a wall. Joins of any kind can be trouble spots that rainwater will exploit!

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Get in touch!

Ready to start a project or require more information about us?
Call us about your project or problem and we will be happy to help.

Call us today on:

0330 3200 240
Or email us here