Drainage - Puddle of water under the dining room fl

[paulimm]

I recently noticed a lot of water appearing under raised floorboards in our dining room extension. I know water pools on the patio area and by the walls, and to try to ease this I put in a gulley with gravel in around the base of the dining room walls to try to catch the water.

We had particularly heavy rain yesterday as I mopped up the water it reappeared through the concrete. I know I need to get someone in - but who would be an expert on solving the problem? A builder, a plumber, a damp company?

Any help/advice appreciated

[Tony McC]

I think a builder or structural engineer should be the first option as there should be no way for the surface from outside to find its way in and under the floorboards. Is the sub-floor/solum lower than the patio outside? Is the patio high relative to the dpc?

[paulimm]

Thanks for the quick response.

I think the water must have come in via the walls or up under the floor (hard to tell which). The sub floor is lower than the patio outside and the patio outside is very near to the dpc. This was mentioned in the survey of the house - and we dug a ditch around the edge of the wall which we filled with gutter piping and pebbles and sealed with sealant and cement, to stop the water collecting by the wall.

I noticed when it rained this ditch was very full. what would be the usual course of action buy the builder - is it a big job usually? As the area is dry now I don't think it is a water table issue do you? Is it possible that water which pools in an area 1.5mtrs from the wall when it rains could seep under the patio and cause this?