No DPM in front porch

[ScottB2]

Hi I'm new here so please be gentle ;)

I think I've open up a can of worms

So our extended front porch has always been freezing in winter & this year I decided to do something about it. I suspect it was never professionally done & that the old owner did it himself & going by his other 'improvements' I don't hold much hope for anything going well.

I've removed the old tiles, which I found water on the back of some, and tried to dry out the room with an extra heater. There was no insulation behind the flimsy paneling covering the stonework & so far I've not found any evidence of a DPM for the inside concrete floor. The DPC from the outside wall is at the same level as the inside floor so I think damp has just been coming through the walls & from under the concrete.

I need to know what my options are for damp proofing the floor please? Should I dig out the floor, lay a DPM & refill with concrete or is there a rubberized paint on DPM that might work? I want to build out the wall by 50mm (cant go any more due to position of the front door) insulate the walls & cover with 9mm ply and put down 5mm foam insulation & waterproof laminate flooring. If I lay a DPM does it need to go up the inside of the stonework & then I insulate over it?


As I started

scottb2 a.jpg (96.23 KiB) Viewed 5688 times

After removing tiles & panels (note: that surface on the floor is 1/2" thick sand base which I've partly removed as it was blown)

scottb2 a.jpg (96.23 KiB) Viewed 5688 times

Outside wall

scottb2 c.jpg (160.11 KiB) Viewed 5688 times

Any help will be much appreciated, thanks.

[cotswold builders]

couple of coats of synthpruff should sort the floor out

[ScottB2]

Thanks for the reply.
Will that be ok do cover the floor & walls, also will it be ok at the join from wall to floor where the DPC is? (as in it shouldn't let anything through?) As some of the screed has come off already would it be best to remove the rest, paint on the Synthprufe then put new screed down or will it be ok just putting the 5mm flooring underlay directly on the Synthprufe? Or should I just replace the blown screed & paint over the whole lot? How far up the walls do I need to go?
Sorry for all the questions.

[ScottB2]

The removed screed so far, my hammer drill is dead so borrowing a mates on Monday.

scottb2 d.jpg (92.03 KiB) Viewed 5688 times

I dug a bit out near the edge & the concrete doesn't look that thick :(

scottb2 e.jpg (123.05 KiB) Viewed 5688 times

[wine~o]

Save your mates hammer drill for fixing shelves. You need summat like this to break that up

https://www.screwfix.com/p/energer-enb4 ... 240v/63303

[ScottB2]

His drill is a corded one with chisel function & I was going to use it initially to remove the screed. That hole I pictured I did just with a large screwdriver & claw hammer so I don't think it's too hard. Any suggestions about what the best option would be to damp proof this area?

[ScottB2]

When I was removing more of the screed there was a part of the floor that sounded a bit different so I chiseled more & there was basically a partial void under the floor (4-5" deep).

If I have to break up & remove the existing concrete floor how deep should I go? I've researched a bit & as far as I can see I'd need sand as a base, DPM, 50mm Celotex type Insulation (+ 10mm around the ext wall edge), 100mm concrete slab, screed to level then I can lay the underlay insulation (5mm) & then laminate floor? Does this sound right?

That's an SDS chisel for size comparison.

scottb2 sds.jpg (66.75 KiB) Viewed 5688 times

[wine~o]

Be careful. dig it all out but watch for cables/soil pipes.

[ScottB2]

So a local builder in my village came around & he said the easiest option would be to just fill in the hole in the corner then once dry & the screed layer is removed just paint it with Synthaprufe. So that is the option I've gone for as I never wanted to spend loads on it. I've filled in the hole which surprisingly took 1.5 bags of ready mixed concrete after I removed all the loose rubble & dug down to about 4" depth. So now I'm just waiting for it to dry, which in this temperature might take a while :( Once dry I'll put a thin layer of self levelling compound down the underlay & laminate floor.

[ScottB2]

No more progress pics but I've put down a layer of self leveling compound, I might have had it not quite runny enough but it's still got slight bumps & trowel marks where I spread it out. Not to worry. It should have taken 3-4 hours to dry but has been down for 3 days now but took ages to dry out, even with a heater on in the room! There is still a dark patch on the floor where I think water is leaching through part of the wall. Must be the cold from under the slab. I've also smoothed out the wall with some mortar to help the Synthaprufe when I apply it. Knowing my luck it'll take a couple of days for each layer to dry :( I'll be investigating the outside where the damp is getting through but a quick look I can't see anything obvious. My only thought is the slope on the outside concrete might not be helping as the end of the concrete seems to correspond with the same area inside, maybe I'll have to extend the concrete slab outside? That's a summer job though.

[ScottB2]

The damp patch inside has finally dried out over the last few days with the dryer weather. Last night I repointed the bricks below the dpc on the outside of the wall as it needed to be done with the wet looking forecast. Hopefully this will stop further ingress of water inside & I can get the Synthaprufe down & walls finished.

[ScottB2]

So it's been a while but with holidays, a sick father-in-law, work commitments & general life getting in the way I hadn't made much progress. I can report though the damp is now gone, Synthaprufe done, laminate flooring down & framing for the bottom wall complete I can now tackle the walls above the stone walls. If I ever see the previous owner again I'll let him know just how much of a c*$# he is !

Honestly, this guy bodged everything & I bet he just used what ever he found laying around. From crappy old offcuts of celotex (foil side facing out), scrap wood (half painted), & no type of builders paper what so ever it's no wonder it was so damn cold in there. You can see by the pics there is no structured form of framing, it's just chuck a bit in here & a bit there. The old 4x4 used in one corner was a bit short so he just used another bit of board to make up the distance & god knows what's going on with the small piece of wood added in to the angled bit coming from under the ceiling plasterboard.

I've got a feeling the ceiling is going to have to come down to see the extent of the probably sh*t attempt at framing up there

Corner by the door

scottb2 1.jpg (57.77 KiB) Viewed 5697 times

Opposite corner (see notched 4x4 & random piece of wood)

scottb2 2.jpg (43.17 KiB) Viewed 5697 times

Window set right against the brick wall, probably why the window never closed easily as no weight bearing frame I'm going to be removing the window, framing it properly & moving it over.

scottb2 3.jpg (75.26 KiB) Viewed 5697 times

If I'd known it would have been as bad as this or big a job I honestly would have not even started but now I kind of have to see it through to the end & put it right

I have attached the pics directly rather than thru imgur Mod 2.

[ScottB2]

Talked to my builder neighbor & he said the previous owner definitely had no idea what the F he was doing. He said I need to brace the joists from the roof then remove the windows & frame them in properly with 4x2 so everything is more supported & definitely replace that dodgy corner post. In the mean time we've been busy with the front garden filling in a pond, moving around a sh*t tin of earth & removing stones. We also removed a flowering cherry tree & an absolute b*stard of a Conifer tree stump (took nearly a week of digging!) but I'm glad it's done & we can now lay the turf.

We did all of this by hand too.

[moderator2]

@ ScottB2 Please attach the images by the attachment function on this forum. Imgur can and do move or remove images which would make this thread useless in future. I've just spent 1/2 an hour attaching your pics to the thread. Thanks.

[wine~o]

didn't get notifications of replies to this thread.

Window needs a lintel let in. interna woodwork just ...

Btw was that a 2 storey house before the previous owner started his bodges...