LBC update required?

[oxonvale]

Hello all,

Within the scope of an approved LBC was provision to remove bituminous paint that has previously been applied to the external elements of the timber frame. The stated methodolgy within the LBC was to use Peelaway. Subsequent sample testing has shown that this will not work, soda blasting has been suggested.

Do you think the change in methodolgy needs to be notified to the local CO? Or we are fine to continue as we the intent was already approved?

 

[Cubist]

A couple of questions;
- who stipulated the use of Peelaway; you, your contractor or a LBCemployee?
- Is the house listed?

 

[oxonvale]

I did, on the basis of precedent of similar houses in the same village. LBC = listed building consent - I should have made that clear.
Yes, the house is listed.

 

[Cubist]

it would be worth having a chat with your Conservation Officer but I would think he/she would be amenable to other methods. Personally I would want to test the soda blasting approach before committing. While its less aggressive than sand its possible that it will still strip/remove much of the softer elements of the timber.

Forgive my confusion the LBC acronym is also commonly used for Local Building Control.

BTW - what materials have been used for the infill panels between the timbers?

 

[oxonvale]

we have brick infill, which has been painted with modern exterior emulsion in the past (and is now flaking off). We have consent to Doff that paint off and re-apply limewash (which is visible where the paint is peeling).

 

[Kearn]

Hopefully you can get an email approved change of approach, but they will need consulting.

You can’t hide abrasive blasting externally! And god it’s a horrible weeks work… trust me!

It depends on the CO, blasting is often disapproved of, sometimes for good reason as there are many aggressive do it quick, hard and fast outfits.

The chemical softening approach has its place, but it’s small scale internal smooth timber, it would never work on external weathered timber. You would literally be there forever and not achieve your goal.

A good CO, and client, will always get tests done beforehand, CO will likely require this and the results. You’ll pay for them. Stonehealth and Restorative Techniques are the two suppliers of the common kit, both have accreditation schemes for their kit usage and hold approved operator lists. There are other folks, I currently have a gem of a gentleman right now cleaning the inside of our property. He is using sand, and does so on G1 buildings approved by all the necessary bodies and lectures at various conservation bodies. Happy to share details, but it won’t be price competitive so it depends on your building and outlook.

soda/sand/shells etc… there’s a lot of intentional confusion here, the media is important, but not as much as the operator and their care, experience and skill. Ignore dry ice, it’s extortionate, and not dry and does damage.

 

[Cubist]

we have brick infill, which has been painted with modern exterior emulsion in the past (and is now flaking off). We have consent to Doff that paint off and re-apply limewash (which is visible where the paint is peeling).

My reason for asking is that any form of blasting can also erode the plasters or mortars used for the infill panels and potentially cause rain-water penetration and possible damage to the timbers. You'll need to be ready to examine and repair them as needed if you proceed with a blasting approach.

Personally I dislike brick infill panels because they are quite permeable and in effect capture any rain-water some of which descends and collects in the lower courses next to the timbers before it can be carried away by natural airflow. Suitable paints or limewashes are vital for brick panels in my view.