Concrete blocks being corroded with rain water from shed

C

chlipps

Registered User
Messages
404
My garden shed is up on concrete blocks. Some of the blocks on one side are being corroded/eaten by the rain water dripping onto them from the shed roof?.. Is there something in the felt that is contributing to the corrosion... How can I prevent it?. Any advice appreciated
 
Haven't come across that one before, unless there is some acidic secretion on the roof itself. Bituminous roofing felt shouldn't cause a problem. Perhaps some by-product from rotting leaves, but it still doesn't ring true. Even is severe conditions, concrete products tend to be robust and durable.

ONQ.
 
Are you sure that they are concrete? Like ONQ, I've never herad of concrete being eroded by water dripping off a shed.
 
ONQ... no leaves near it... just rainwater direct off the roof

BillK...yes definitely concrete blocks

bullworth... not all of the blocks are being corroded. All bought the same day from same pallet.. The mortar that I used between them still there but the blocks dis-integrating slowly into a pile of chips (slowly being over past approx 5 years)

I have never seen something like this to happen previously... maybe the mix in these few blocks was not up to standard.

I must do a repair soon but have been slow to do it as wont match in with the other blocks, without plastering all of them.

Thanks for the feedback
 
Is the rainwater only dripping on the bad blocks or also on the well preserved blocks ? Maybe if its something acidic in the water you could install a gutter on the shed ?
 
You can get erosion of blocks, paving etc that are located in a drip line off a roof. Fixing a gutter will stop the problem.
 
Did you tell the builders providers they were for a shed base? If so they probably send you the worst blocks they had. I made that mistake before and nearly ever block was poor.
 
Thanks for replies

Didnt tell builders providers what i wanted the blocks for... as never expected an issue like this to arise with rain water.. I will have to look into a gutter option and hopefully will get something that looks ok on a standard timber shed... or maybe drip tray at low level and let that cover up the corroded blocks... thanks again
 
....you could have been given 'seconds' which quite often are batches of blocks, usually made on wet days, where the cement 'slumped' to the end of the block. I've seen them where they were very dense one end, and almost vacuous the other !

To understand this, you need to know that blocks are made on their ends, standing in the yard. Get a crap, wet day and..........all the 'good' gets washed to one end.

Not the end of the world, though - I presume it's a timber shed you have on them ? As mentioned, a gutter/downpipe, and even, if you're really bothered, you could put on a layer of plaster, to keep the worst at bay.
 
You must log in or register to reply here.
Back
Top