Damp Internal Wall and Floor Rotten and Crumbling? Advice please! Damp can be a major issue in the home. Find answers to questions or post your own here.

[lolole16]

Hi there

Can someone please help me understand what may be going on in my property.
Myself and my husband bought a 1930's semi detached house and have just recently had a DPC injected to all external walls. However, when we lifted the kitchen floor tiles, the floorboard by the internal wall (joins to a back lounge) was wet and rotten and crumbled away leaving a hole in the kitchen floor. Is anyone able to tell me what kind of damp they suspect this may be? I didn't think you could get rising damp to an internal wall?

Many thanks

[welsh brickie]

you can get damp in any wall, The damp installers should have assessed the damp in the walls throughout the property and injected where nessasary, The damp and rot in a in a wooden constructed floor is usually caused by lack of ventilation, so check that all the airbricks are clear from debris, inside and out, and more should be installed if possible

[lolole16]

Many thanks for your reply I really appreciate it. That makes sense as there was decking to the rear of the property which was blocking all the airbricks. We've removed the decking now but suspect floor in kitchen will need a lot of work. Thanks for your reply, would you mind answering another query?! We had damp in the front bay window downstairs, the plaster was bubbling and falling away. The damp man stripped the plaster back to brick and treated damp. It's been 5 weeks since the work now and the plaster in the worst parts is taking ages to dry and is starting to bubble out in parts and white fluff has appeared on some parts of the plaster which is wet. Do you know what that is?
Thanks for all your help.

[welsh brickie]

the white stuff is salt coming out of the material, the technical word is efflorescence, It should not be wet, it may be the chemical bubbling out of the brick.