Survey results, do I need a chemical DPC?

PeonySugar

So we are in the process of buying a house, and and we have just got our survey results back. One of the odd things that has happened is that the air bricks were taken out in the ground floor. The driveway at the side of the house was also built up so its higher than the bitumen damp proof course that's there, resulting in damp, and rotting floor joists. The joist ends will need replacing, but I'm wondering if the chemical dpc that the surveyor recommended actually needs doing? If we dug down to below the dpc that's there now, and put in more air bricks would this solve the problem?

flashg67

I'm not a builder but have 'done up' houses in the past. There's a lot written about the merits, or otherwise of DPC's. In your case. sounds to me that you're on the right track - digging a channel below the dpc to allow drainage and stop damp tracking through should do the trick?

Davesnave

The surveyor may have suggested a chemical DPC because they thought you'd rather do that than lower the surrounding ground. If you are prepared to do the latter and the existing DPC is sound, it will be a good solution.

You'd be reinstating vents anyway, I'm sure.

robotrobo

PeonySugar wrote: »

So we are in the process of buying a house, and and we have just got our survey results back. One of the odd things that has happened is that the air bricks were taken out in the ground floor. The driveway at the side of the house was also built up so its higher than the bitumen damp proof course that's there, resulting in damp, and rotting floor joists. The joist ends will need replacing, but I'm wondering if the chemical dpc that the surveyor recommended actually needs doing? If we dug down to below the dpc that's there now, and put in more air bricks would this solve the problem?

When we purchased our last house some 25 years ago, it was built on a incline. And i said to my wife at the time "well at least we will not get flooded living here" how wrong was i , a fireman as well at that time.
It was like yours ,the air bricks had been blocked up over the years & eventually all the joist ends had gone rotten, i thought at the time that the old couple had sealed off the vents to keep the cold draughts out.
We completley made good the house over the years , including side extension 2 storey, new windows , doors , pebbledashing , you name it , i did it over the years we lived in this by now a very smart semi det 4 bed house.
Then about 12 or more years later there was a big storm & the rain was lashing it down & the water was comeing off the hills some few miles away, the water was gushing down the roads at the side of us as we were the last semi on to the cross roads, it was lifting the very heavy rain drain covers in the middle of the road. it was now over the kerbs & entering the gardens .
In our garden we had the sewerage 5 foot x 2foot manhole that collected all the waste from our neighbours toilets etc, the gushing water backed up in to this & my garden started to flood , & you guessed it , the water was filling the void under the house with all this filthy water , it finally finished the flash flood & when i lifted the floor manhole the water was inches from comeing up through the floor.
I did pump it all out , i did raise the vents in the outer wall by a bricks height, i did sell the property some ten years ago .
maybe this could be why you have this raised up over the dpc course & the vents removed , probably not, but going back to when i was buying my property all those years ago , i would be saying probably not. All the gutter top water drains , 4 in total were back filling & flooding the garden & comeing over the top of the air vents."happy days":eek: