Five costly building mistakes and how to avoid them - by Surveyor Stephen Reilly

Bell Ingram’s building surveyors are passionate about all types of buildings, painstakingly working to preserve and restore them for future generations and making them good for all types of modern-day use.

The services we provide are two-fold, firstly; conservation and restoration of historic and listed buildings including full surveys and contract administration, and secondly: project management of new builds, refurbishment and conversions.

Bell Ingram’s expert building surveyor Stephen Reilly highlights five common mistakes that can cause big problems for owners of traditional and listed properties … and how to avoid them.

1  Pointing

The best way to maintain stone walls is to ensure that any repairs are on a ‘like for like’ basis. This principle will reduce the likelihood of defects such as the erosion of the stonework where a harder (probably cement based) pointing material has been used.

Being a soft stone, the red sandstone will erode, however the harder pointing will have trapped water behind it and the freeze/thaw action in winter will have accelerated the rate of erosion.

Given the extent of the surface erosion it would not be unusual for a new lime harl finish to be applied to the chimney stack rather than trying to repair the stonework.

2  Windows

When considering refurbishment of traditional vernacular buildings the replacement of the windows can be very tempting, particularly with ‘maintenance free’ uPVC units.

This may seem like a good investment but how long will they last before the plastic yellows, the gearing breaks and the weatherproof gaskets fail? Most likely the day after your 10 year guarauntee runs out! 

I have seen very few timber windows in functioning buildings that are so badly decayed that they need to be completely replaced.

In this picture, the ground floor windows are replacement uPVC units while the first floor timber window (which may have been there for 100 years or more) only needs a lick of paint.

Aesthetically the new uPVC units certainly don’t add to the character of the building.

3 Lintels

This photograph is of part of the interior of a Category A listed building (constructed in the early 17th Century) which was badly affected by fungal decay due to the failure of the roof covering which allowed water ingress. The building is of stone construction with a lime-based mortar.

There are several issues shown which are not in keeping with good conservation practice and would not normally be acceptable for HLF/HES grant aid.The original timber safe lintel(s) has been replaced with a concrete unit.

Of course when you have timber lintels then you should make sure that they are protected from the elements, a coat of paint is better than nothing. I can only hope that it was not a tradesman that created this window slapping through the brickwork of the building in the photograph opposite.

4  Bats

Rural buildings are a favourite roosting spot for bats which are a legally protected species across the UK. This means you may be committing a criminal offence if you: intentionally or recklessly disturb a bat in its roost; damage or destroy a place used by bats for breeding or resting even if bats are not occupying the roost at the time; intentionally or recklessly obstruct access to a bat roost.  A simple check if droppings are found could confirm the presence of bats in advance. Something worth knowing when you consider that breaking the law can result potentially in six months in prison or an unlimited fine.

5  Render

In the UK external silicone renders and finishes have increased in popularity over the last 30 years or so. They claim to provide a durable, weatherproof, breathable, natural finish, the modern equivalent of a lime harl. Renders were originally used to cover poor quality work, however modern silicone (and acrylic) renders are used to create architectural features with sleek lines and stunning finishes, which they do.  These renders can, however, contain organic ingredients which under the right environmental conditions can support the growth of fungi, mould and moss resulting in discoloration of the render finish such as that evident on the building pictured (dark streaks between the ground and first floor windows).

Unfortunately washing the render with a fungicidal wash did not remove the organic growths nor the staining and the render had to be coated with a specialist paint system to reinstate the desired finish. The cost of this work will not have been anticipated when the building was constructed 14 years ago.

Article posted on 19/11/2020

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