besser blocks and salt damp/rising damp

[Tonz]

working on a 60's building erected from besser blocks that now have bad salt damp rising.....
This building is right on the coast, literally high tide I could be fishing from the verandah.
The community group that owns it have run themselves financially ragged and have zip to pay buy anything.
Ive googled enough and youtubed to have a good idea how to remidy the situation.

What the 'specialists' dont tell you is
1. how long the 'synthetic' (for want of a better word) membrane will work
2. what happens to the bricks/blocks below the membrane...do they continue to crumble with salt damp and then (given to reason) eventually collapse? if so what happens to the remaining wall.

I see this stuff working well for a period of time but then.....

[Citroënbender]

Are you financially exposed by this? I hope not.

My personal opinion is, the building is approaching the end of its practical life. It’s like strata on a smaller scale; putting off the necessary and not having enough in the kitty.

Investigate having one section of structural wall up to the DPC replaced at a time with an engineered placed concrete structure. Then price the aggregate cost against bailing and also against rebuilding in one hit. Older structure, probably got asbestos in places, too.

[roKWiz]

Besser blocks, concrete, saltwater environment what a great combination.

[Tonz]

[simon varley]

my old man built his retirement fund underpinning subsiding buildings. Not quite the same here I know but - run!

[roKWiz]

Originally Posted by simon varley

my old man built his retirement fund underpinning subsiding buildings. Not quite the same here I know but - run!

I reckon there is some big money to be made along the foreshore in Newcastle in the future.

[Citroënbender]

I just literally LOL’d.

What an understatement.

[roKWiz]

Yes, there's good reason why breakwaters are built using granite.

A few of Sydney's waterside heritage buildings are gradually decaying from rising, falling damp and water ingress.

One example....I worked on was the Contemporary Arts building (ex Maritime Service board building) at Circular Quay, the above mezzanine sections are sandstone with the bottom foundation stones built from south coast Balmoral granite.
The complete foundation walls are 3ft (910mm) thick made from solid polished granite. Foundation stone like some other local buildings there have not moved or suffer from water damage.

Around the top of the building is a large sandstone parapet with a cross section of 16in (400mm) over the years this has gradually soaked in all the salt and freshwater through all the end joins where the blocks of around 5ft (1500mm) long each have swelled, forcing the corners of the walls to push out over the end of the building roof.
The only way to address the problem I found was to take a cut of 100mm out of each piece and gradually block and tackle them back into position
along the wall, finally using a copper sheath over the end joins with clear epoxy sealer. It will buy some 20 years but eventually it will require a complete parapet replacement, each stone being 2-3 tons up at 8 storeys high, glad I won't be doing it.
The pushed corners were overhung by up to 200mm when I first inspected them creating a danger situation.

Another reason not to used porous materials in a wet or frosty environment.