Drain channel not level

[kay01]

Hi there,

My builder has finished laying porcelain tiles in my 8m×4m garden with 5mm spaces. The drain channel is in middle of the garden as on the other half i am planning to lay artifical grass. My builder left 30mm space between edge of the tile and channel, reason he has given that he has kept the channel slop in middle where the gully/hole is, which then take the drained water to the main drainage system and if he leave 5mm gap between the tile edge and channel (thats what i want) the channel won't be flushed from middle and it will look awkward, and if he finishes the slop and flushes it then water won't be drained effective. I believe if i compromise on 30mm and fill the gap with grout, the grout won't stay and will keep coming out in long run. I am very confused and request can any experienced builder please suggest some thing.

Regards

[Andehh]

I WONDER if you could use am External grade colour matched silicone sealant type, applied carefully and smoothed with a silicone spreader? 

 

Even if it needs to be replaced every few years it's cheap, quick and easy to do? 

[markc]

I would be more concerned that the tiles are right up to the brickwork and only just below DPC. Water splashes are likely to cause damp in your wall.

really needs a channel cutting between tiles and brickwork, fill this with peddles etc. to stop water bounce

[Canski]

29 minutes ago, markc said:

I would be more concerned that the tiles are right up to the brickwork and only just below DPC. Water splashes are likely to cause damp in your wall.

really needs a channel cutting between tiles and brickwork, fill this with peddles etc. to stop water bounce

Yes this could be a problem. 

[Dave Jones]

1 hour ago, markc said:

I would be more concerned that the tiles are right up to the brickwork and only just below DPC. Water splashes are likely to cause damp in your wall.

really needs a channel cutting between tiles and brickwork, fill this with peddles etc. to stop water bounce

 

could be a tray there moving the DPC higher........

 

with regard to the channel, id want it tight as possible between the tiles so there isnt a need for grout as it wont stay there. The plastic swells in the sun and cracks it as its soo thin.

 

[kay01]

53 minutes ago, Dave Jones said:

 

could be a tray there moving the DPC higher........

 

with regard to the channel, id want it tight as possible between the tiles so there isnt a need for grout as it wont stay there. The plastic swells in the sun and cracks it as its soo thin.

 

But what can be done about the non flushed middle of the channel if brough closer to tiles

[Canski]

water will run out of the outlet even if it's level OK there may be a slight pool in the base of the channel but who cares ? It's below the grid. My guess is that maybe they put the channel drain in too early and have miscalculated the gap and are now trying to fob you off.

Edited February 22, 2023 by Canski

[markc]

If the tiles are level you generally set the drainage channel level. It’s not like a foul drain that needs to move solids

[ToughButterCup]

There are a few issues here, some of which you identify, and one possible issue that @markc noticed

I think (collectively) we're saying

• .Don't worry about the drain: it will work even if its perfectly level
• You'd have liked a 5mm gap (not 30mm) between the paving and the drain: sorting that issue out would be costly
• The paving stones appear to butt up against the house: that could lead to damp inside the house because of rain splashing on the paving. Its widely regarded as good practice to have a 'splash strip between house and paving.

The last issue above is the most important by far. Looking (squinting) at your photo, it seems the floor level (Final Floor Level , FFL) isn't that much higher than the patio.  I may be wrong. Ask the builder where the Damp Proof Membrane is (DPM) It should be  100 mm or so above the pebble splash strip.

 

My instinct would be to

• ignore the 30mm gap between flags and drain (because it will  cost a good deal to rectify)
• get a 120mm wide splash strip inserted between  patio and house.

Cost of that : 1 days labour, and some bags of 10mm shingle - say £200. Better that than the the alternative.

[Carrerahill]

5 hours ago, kay01 said:

Hi there,

My builder has finished laying porcelain tiles in my 8m×4m garden with 5mm spaces. The drain channel is in middle of the garden as on the other half i am planning to lay artifical grass. My builder left 30mm space between edge of the tile and channel, reason he has given that he has kept the channel slop in middle where the gully/hole is, which then take the drained water to the main drainage system and if he leave 5mm gap between the tile edge and channel (thats what i want) the channel won't be flushed from middle and it will look awkward, and if he finishes the slop and flushes it then water won't be drained effective. I believe if i compromise on 30mm and fill the gap with grout, the grout won't stay and will keep coming out in long run. I am very confused and request can any experienced builder please suggest some thing.

Regards

I think the drainage is the least of your worries.

 

Those slabs run right up to the house and almost at or maybe above DPC. I cannot see any tell-tale signs to suggest it is above these slabs. 

 

Anyway, looks like he is using excuses for lazyness/poor work.

 

If I had been doing that I would have been lower for starters and I would have sloped the whole lot away from the house and hard up against the drain channel. He has screwed up the levels and now uses lame excuses to try and conceal his failings. 

 

 

[Dave Jones]

channels are designed to be laid level they have fall built in.

[Mr Punter]

1 hour ago, Dave Jones said:

channels are designed to be laid level they have fall built in.

 

Some do, most don't, especially those for small resi projects.

[MJNewton]

1 hour ago, Dave Jones said:

channels are designed to be laid level they have fall built in.

 

Not modular ones like these, otherwise the 'outlet' of one section would be below the 'inlet' of the next...

 

(Notwithstanding that though, a fall is not all that important as others have already mentioned)

Edited February 22, 2023 by MJNewton

[kay01]

18 hours ago, ToughButterCup said:

There are a few issues here, some of which you identify, and one possible issue that @markc noticed

I think (collectively) we're saying

• .Don't worry about the drain: it will work even if its perfectly level
• You'd have liked a 5mm gap (not 30mm) between the paving and the drain: sorting that issue out would be costly
• The paving stones appear to butt up against the house: that could lead to damp inside the house because of rain splashing on the paving. Its widely regarded as good practice to have a 'splash strip between house and paving.

The last issue above is the most important by far. Looking (squinting) at your photo, it seems the floor level (Final Floor Level , FFL) isn't that much higher than the patio.  I may be wrong. Ask the builder where the Damp Proof Membrane is (DPM) It should be  100 mm or so above the pebble splash strip.

 

My instinct would be to

• ignore the 30mm gap between flags and drain (because it will  cost a good deal to rectify)
• get a 120mm wide splash strip inserted between  patio and house.

Cost of that : 1 days labour, and some bags of 10mm shingle - say £200. Better that than the the alternative.

Many thanks for your detailed guidance.

To build a splash strip I have to cut and remove tiles which i dont prefer and on the other hand i like butted tiles. DPC is just above the tile its clearly not 100mm but 25mm. I spoke to my builder and he suggested tile skirting to prevent splashing. In your expert opinion if i leave DPC at 25mm and get 100mm skirting done, would it be enough measure taken to prevent damp, though its a cavity wall.

Many thanks in advance

[markc]

1 hour ago, kay01 said:

Many thanks for your detailed guidance.

To build a splash strip I have to cut and remove tiles which i dont prefer and on the other hand i like butted tiles. DPC is just above the tile its clearly not 100mm but 25mm. I spoke to my builder and he suggested tile skirting to prevent splashing. In your expert opinion if i leave DPC at 25mm and get 100mm skirting done, would it be enough measure taken to prevent damp, though its a cavity wall.

Many thanks in advance

Noooooo! Tile skirting would bridge the DPC And hold any water running down the brickwork. 

Edited February 23, 2023 by markc

[ToughButterCup]

Morning. I'm very far from expert. Hard bitten maybe, but not expert.

 

@markc's point above is the key issue. A splash strip can be made to look really nice, is open to the air and extremely cheap. A tile strip risks trapping water behind it, and if it does so, guaranteeing damp problems in years to come.

 

And I bet you one month's salary that the bits of mortar that fell off the external wall (during construction) bridge the gap between the outer and inner walls . Your builder appears to me to be less than careful about attention to detail.

 

All the published official guidance says that a splash strip must be provided.

 

I'm using my mobile phone to write this. If I was on my PC, I would link to that advice for you and I may be able to do that later on today when I fixed my PC.

 

Have a good look at the range of aggregates that  are available for use in a splash strip. I bet you can find some that you would like the look of. They are all much cheaper than tiles.

[kay01]

Thank you all, I had my BCO visit today and he pointed out the butted tiles and suggested a splash strip which my builder agreed to do..... happy days!!!!