Porch - Paint Blistering

[Martin Quinn]

Can anyone help me out with some general advice?

I have a upvc external door and then an internal door, in between the two doors is a small porch area that has been painted by the previous owner. The paint has started to blister and I am wondering why? Is this simply due to the moisture from the brick?

What is the best way to treat this, sand it down to remove the old paint and then re-paint?

Thanks to anyone that can provide any tips.

 

[Martin Quinn]

Sorry I should have also mentioned that it is the brick work that has been painted. There are also dark patches in the paint work.