Patio and dpc - "blocked air brick"

[gb123]

i really would appreciate an experts view (in laymans terms) to a problem i cannot seem to get to the bottom of !

about 3 years ago, i had a new patio laid and ever since then, i have have damp smell in my house after it rains.

my house is rendered to the ground so it is not obvious to see where the damp proof course buit my feeling all along is that the patio is not far enough below the damp proof course. the air bricks actually sit at gorund level and i think these are the top course of the damp proof course.

i finally bit the bullet today and paid £250 for a surveyor to come round. he told me that yes the patio was too high but this was not the main problem, he said (after i had got the living floor boards up) that he could not feel any air flowing under the floor boards as you would expect from the air bricks at the front to back (or vica-versa). it was quite a still/warm day though !

i have no reason to disagree with the surveyor but as you can probably tell i have no knowledge of this subject at all.

i would really appreciate any views on this as i cannot put up with this any longer !

many thanks in advance.

gb123

[lutonlagerlout]

airbricks are 99 times out of 100 below DPC so that probably isnt the problem,you do need to have sufficient air flow under floors in roofs and anywhere there is timber that can rot.
possibly when the drive was laid they broke a pipe or something underground and thats now leaking,hard to tell without looking
do the flags fall towards the house or away from it??
if they fall towards it that could be a problem
hope this helps
tony

[gb123]

thanks tony.

the air bricks are below the DPC (the DPC is on top of the air bricks) .

would i expect feel a draft (i.e. the air flowing from the air bricks) if i put my hand under the floorboards ?

thanks again,

[lutonlagerlout]

yes , a daught means there is air flow,which stops your floor from rotting. makes the house cold tho,
regards tony

[Ross-Paving]

Hello GB123,
First thing, are any of the air bricks visible along the outside of the house? if not, now that you've lifted the floor boards have a look under and see if you can locate any from the inside - judge the distance below the floor level and transfer that to the outside and check again.
As for feeling a draft under the floor! if your hand was right next to the air brick you would feel something but not if in the middle of the house, especialy if it was a calm day.
Pay particular attention to the areas adjacent to the patio. Did the surveyor carry out and checks for dampness on the walls next to the patio area?
You need to locate the source of the dampness and then consider remedial options - might not be the patio, maybe a blocked rainwater drain or even a problem in the roof, consider everything and anything but find the source of the problem.

[gb123]

firstly, thanks for your response(s).

i have had both the roof and the gutters checked out and no problems were found. i really am just worried about the patio though and over the weekend i found another couple of things that make me even more suspicious .

1) the house next door's patio (the other half of the semi detached house i live in) looks about 10cm lower than mine (i do live on a bit of a hill and they are down the hill)

2) it looks like the new patio has been laid on top of the old patio as after poking about a bit, i can see the old stones and the base they are on is about 8-10cm below the top of the new stones.

the surveyors report does point to the height of the patio and also that there does not appear to be enough of a fall away from the house. i know i am getting paranoid here and the guy was a qualified surveyor, but he did say about feeling a draft under the floor so i starting to question everything !!

thanks advance everyone... i really do appreciate your posts !!