Buying a house with previous basement flooding

Brentwood1

Hi All,
I'm currently in the process of buying my first house and have just received the searches from my solicitor. 
After reading through the paperwork, the only real concern is that the property has had two previous occasions of surface water flooding in the basement, although fixed by the insurance I don't want this to impact me in the future. Below is a timeline which has been provided by the vendor. 

Oct 2014 - Excess water extraction pump in the basement was inadvertently switched off prior to vacation. There was a storm during this period and water collected in the Basement. The insurance company paid for removing water and refurbishing. Since that time improvement/refurbishing & a new sump pump have been carried out.
May 2018 - Neighbours basement had a flood, which was left untreated and 1 foot of water collected in their basement caused damp in our adjoining basement wall. The insurance company paid in full and walls were damp-proofed with new floor to ceiling tanking.

Having had a look at the property myself, the basement is in immaculate condition and looks all brand new. However, I did smell a little damp in the basement.

I'm planning on having a level 3 building survey, but I know that they are not a damp specialist and with everything being visual and only damp readings taking place. I have my concerns that they may not be best placed to advise me on if this can be something to worry about in the future. 

A quick home insurance quote on the property came in about £450 p.a. 

I'm not sure on the best approach to take and whether to start looking for a different property? I do like the house very much, i just don't want to be faced with future flooding problems in the future. Any advice is greatly appreciated. 

dimbo61

What do you hope to put in the basement ?
Has it got electrics 

Brentwood1

Hi, 
The basement has been labelled as a study/bedroom - therefore, I would like to make full use out of the space. 
It does have electrics, lights and heating.
Thanks

AdrianC

The fact there's an "excess water extraction pump" in the basement says everything.
The insurance claim because it got switched off underlines it and adds several exclamation marks.
The fact it smells damp just grabs a highlighter pen.

It's very simple...
You dig a big hole in the ground, below ground water level, and it's going to fill with water.
You line that hole with bricks, and the water will eventually come through the bricks.

All "tanking" does is to put a layer of waterproofing on the inside face of the bricks - the water can't get out of the bricks again. Hopefully. Until you drill a hole, say, that penetrates the tanking.

I don't care what words the EA has used to describe the space on the floorplan, it's a space that I would expect to be less than bone dry... simply because that's what water does. You can't change laws of physics. All you can do is spend a lot of money to try and slow them down a bit.

blue_max_3

I underpinned my basement and installed a sump pump. These days you line the walls with a membrane and basically seal the room off. A perimeter channel feeds into the sump and a pump siphons off the water as it builds. You do not alter the moisture content of the walls and a flood next door would have no impact. You do need a battery backup pump ideally.
I was lucky as the site sloped away from the room, so I was free to let gravity take it's course.