Edpm at edges

[Pocster]

Actually thinking about it ....

 

if if this was done correctly edpm would be up past the final paving block level . Then the flashing would hang over it and sit on the paving .

 

Because my flashing is below ground (effectively ) any moisture that does get in there can’t escape - it’s not breathable .

The expansion gap would allow condensation and air flow under the flashing lip .

 

Have I convinced myself a lie ??? ?

[Pocster]

1 minute ago, pocster said:

Actually thinking about it ....

 

if if this was done correctly edpm would be up past the final paving block level . Then the flashing would hang over it and sit on the paving .

 

Because my flashing is below ground (effectively ) any moisture that does get in there can’t escape - it’s not breathable .

The expansion gap would allow condensation and air flow under the flashing lip .

 

Have I convinced myself a lie ??? ?

I’m taking a vote on this with myself .

I won the vote ?

[Cpd]

How does the area drain ? I am only just starting to realise what’s going on...... yes the Edomite should of been up above the pavers and yes there should then have been the flashing that would have come down close to the top of the pavers but not below them...... sorry but I am concerned that if water can get in without the ability to drain away then it will just keep filling up until it overflows. If the lowest point for it to get out is behind the flashings and into your new cut recess then that’s where it going to go........ water will always find the easiest path. I had assumed that there was some sort of permeable drainage layer below whe slabs and BELOW the height of the top of the EPDM. That way any water would just run out as it got in.  

[Cpd]

Either you want to be able to drain the water away or you don’t want water in the structure. How will it cope if water can get in but can’t get out and you get -10 conditions ? 

[Pocster]

6 minutes ago, Cpd said:

How does the area drain ? I am only just starting to realise what’s going on...... yes the Edomite should of been up above the pavers and yes there should then have been the flashing that would have come down close to the top of the pavers but not below them...... sorry but I am concerned that if water can get in without the ability to drain away then it will just keep filling up until it overflows. If the lowest point for it to get out is behind the flashings and into your new cut recess then that’s where it going to go........ water will always find the easiest path. I had assumed that there was some sort of permeable drainage layer below whe slabs and BELOW the height of the top of the EPDM. That way any water would just run out as it got in.  

 

[Pocster]

Just now, pocster said:

 

Hey 

 

So the layout top down is 

 

pavers 

sand 

chippings 

75mm concrete reinforced 

edpm 

cement board 

expensive insulation 

concrete reinforced 100mm

 

The 75mm concrete is ‘level’ to the other 2 edges of the plot for run off .

plot has slope away from house 

drainage channel with be placed directly in front house and at front of plot ( gate entrance and lowest point )

 

that help ? ?

[Pocster]

21 minutes ago, Cpd said:

Either you want to be able to drain the water away or you don’t want water in the structure. How will it cope if water can get in but can’t get out and you get -10 conditions ? 

Yep agree !

As water is bound to get in then I think that’s why the roofer said expansion gaps - so at least it can evaporate with air flow .

 

Because the ‘roofer’ bodged it ; it’s not like your drawing .

 

[Pocster]

I think my point is even with driveway pavers some water will soak through anyway .

Edited June 7, 2018 by pocster

[joe90]

I think if the pavers are left 10/15mm away from the wall and that gap filled with chippings down to the chippings below it will drain fine.

[Pocster]

2 minutes ago, joe90 said:

I think if the pavers are left 10/15mm away from the wall and that gap filled with chippings down to the chippings below it will drain fine.

Yeah but I think @Cpd is saying “drain where ?” 

This is all above living accommodate so the edpm is the water proofing .

Once rain water gets through and lands on the edpm it is stuck until it evaporates .

I’m not sure what to do now !

[Pocster]

Right !

@cpd i’m Going with you !

so !

ordered more edpm - will lap a piece over existing edges ( and bond of course )

Will take it right up the wall past floor finish THEN will flash it !!

Say YES ! 

[joe90]

So is this drawing not correct?, do you have drainage out the bottom as it shows?

 

 

Edited June 7, 2018 by joe90
Add drawing

[Pocster]

Right!

 

Couldn't get hold of my architect ( unsurprisingly ) but did the SE and asked him. he admitted not his field, but that the EDPM should lap up further and be above the finished paving and then some flashing. He agreed that no matter what I did *some* water would get in if only via the pavers. He said water between the EDPM and concrete was not a concern. He also confirmed water penetration through the concrete wouldn't happen ( I know this to be true as the initial roof is 100mm thick been exposed to everything for years and no water has ever come 'through' it ). So it is all about the edges!.

 

SO!.

 

1) Would it be ok to fill in my angle grinded slots with CT1? ; no way I can get cement in them.

 

2) Will then 'lap' EDPM over his bodge/mess (delete as applicable) right up the wall past the final floor finish

 

3) How do you stick EDPM to EDPM?. I'm fairly sure the guys just stuck primer on both parts ; let it go tack then rollered them. But videos seem to suggest otherwise. Advice welcome here!

 

4) SE also suggested bedding the pavers in mortar!! so no movement and even less chance of water getting through (FFS! that's a load of work compared to the standard method) - still wacker plate can stay in the garage ?

 

@cpd "God it’s painful to see how things are done by supposed professionals" . Tell me about it!. I deliberately didn't do this as I've never done it before and it's a one off i.e. I'm never going to rubber a roof again. Look what happens! - might aswell done it myself; hard to imagine I'd make a worse job of it.

 

Any advice on any points really welcome!

 

[Pocster]

"3) How do you stick EDPM to EDPM?. I'm fairly sure the guys just stuck primer on both parts ; let it go tack then rollered them. But videos seem to suggest otherwise. Advice welcome here!"

 

Right!, splice tape. There are 2 points at which they have joined on the flat bit. 99% they didn't use splice tape. They just stuck a piece over ( will get a photo tomorrow) . So I will cut a square and 'splice' a proper section on top for peace of mind! Then splice tape along base of wall and EDPM up! 

[Pocster]

wine?

[Pocster]

2 hours ago, joe90 said:

So is this drawing not correct?, do you have drainage out the bottom as it shows?

 

 

 

Nope. No drainage. Only drainage it to deal with surface run off. Got to make those edges SUPER tight ! ?

[Cpd]

1 hour ago, pocster said:

1) Would it be ok to fill in my angle grinded slots with CT1? ; no way I can get cement in them.

Filling with ct1 seems excessive as with the new and improved design this are will now be on the dry side of the epdm, yes I would fill it with something and maybe someone will be able to point out a good product, I really don’t know as it’s something I have not dealt with.

 

1 hour ago, pocster said:

Will then 'lap' EDPM over his bodge/mess (delete as applicable) right up the wall past the final floor finish

Remember to trim any stones that will be between the top of the pavers and the top part of the  flashing, do it with the diamond cutting disk, I have a diamond grinding disk for this sort of work and it’s fantastic but not something you would use again unless like me you were a stonemason in a former life. You now have a good opertunity to do this right and have it looking sharp and sweet.  by trimming the stone you can get the flashing as close as possible to the wall, I would then be cutting a large enough slot that the flashing can be mortared in to fit in with existing mortar. you are also able to “hide” some of the walls imperfections by creating a nice parallel  mortar line  with only a consistent amount of the top of the flashing showing , or if the flashing is all the way back you can mortar right up to the top edge,Work out how far the bottom of the flashing should be from the top of the pavers, not my field but I would be looking to keep it between 10-20mm enough for the drip but not enough to be obvious, more an unobtrusive shadow gap. Again not my field and worth checking for pro recommendation. Maybe worth mortaring up from top of slabs to up behind the flashing (prior to flashing going on....) so that your seeing a consistent material rather than bits of random stone and mortar joints. Its an area that you don’t want to draw attention to. Function is the key.

 

1 hour ago, pocster said:

3) How do you stick EDPM to EDPM?. I'm fairly sure the guys just stuck primer on both parts ; let it go tack then rollered them. But videos seem to suggest otherwise. Advice welcome here!

No idea

1 hour ago, pocster said:

4) SE also suggested bedding the pavers in mortar!! so no movement and even less chance of water getting through (FFS! that's a load of work compared to the standard method) - still wacker plate can stay in the garage ?

I would not be putting a whacked enywhere near this.... the idea of whacking anything hard on top of epdm sound like a recipe for disaster, how would you know if the vibration caused a sharp stone edge to cut into the rubber..... I personally like the idea of concrete and then a mortar bed that the slabs are set into as this eliminated a huge area that water could and would sit. Maybe rethink the depth if concrete so that when it comes to mortaring in the slabs it’s exactly the right height for the correct mortar depth needed when laying the pavers, sure there is some set standards for this, it may be worth having some sort of plastic stands or some such thing so you don’t get any of the slabs subsiding as you work along, the stands under each corner just get  lost in the mortar. I have cut up a 50mm slab into lots of squared before and used these as my stands, helped me get a perfect flat surface as I checked the stands with a laser level before I filled around them with mortar and then put the slabs on top, tapped them down and moved into the next line. I think this method will eliminate my concerns about water build up as there will be virtually no where for the water to go and it’s really fit and forget. 

[Pocster]

3 minutes ago, Cpd said:

Filling with ct1 seems excessive as with the new and improved design this are will now be on the dry side of the epdm, yes I would fill it with something and maybe someone will be able to point out a good product, I really don’t know as it’s something I have not dealt with.

 

Remember to trim any stones that will be between the top of the pavers and the top part of the  flashing, do it with the diamond cutting disk, I have a diamond grinding disk for this sort of work and it’s fantastic but not something you would use again unless like me you were a stonemason in a former life. You now have a good opertunity to do this right and have it looking sharp and sweet.  by trimming the stone you can get the flashing as close as possible to the wall, I would then be cutting a large enough slot that the flashing can be mortared in to fit in with existing mortar. you are also able to “hide” some of the walls imperfections by creating a nice parallel  mortar line  with only a consistent amount of the top of the flashing showing , or if the flashing is all the way back you can mortar right up to the top edge,Work out how far the bottom of the flashing should be from the top of the pavers, not my field but I would be looking to keep it between 10-20mm enough for the drip but not enough to be obvious, more an unobtrusive shadow gap. Again not my field and worth checking for pro recommendation. Maybe worth mortaring up from top of slabs to up behind the flashing (prior to flashing going on....) so that your seeing a consistent material rather than bits of random stone and mortar joints. Its an area that you don’t want to draw attention to. Function is the key.

 

No idea

I would not be putting a whacked enywhere near this.... the idea of whacking anything hard on top of epdm sound like a recipe for disaster, how would you know if the vibration caused a sharp stone edge to cut into the rubber..... I personally like the idea of concrete and then a mortar bed that the slabs are set into as this eliminated a huge area that water could and would sit. Maybe rethink the depth if concrete so that when it comes to mortaring in the slabs it’s exactly the right height for the correct mortar depth needed when laying the pavers, sure there is some set standards for this, it may be worth having some sort of plastic stands or some such thing so you don’t get any of the slabs subsiding as you work along, the stands under each corner just get  lost in the mortar. I have cut up a 50mm slab into lots of squared before and used these as my stands, helped me get a perfect flat surface as I checked the stands with a laser level before I filled around them with mortar and then put the slabs on top, tapped them down and moved into the next line. I think this method will eliminate my concerns about water build up as there will be virtually no where for the water to go and it’s really fit and forget. 

Mega ! 

 

Will waste a tube of ct1 for peace of mind ! On the slots !!!

 

Will ‘flatten’ stone faces at ‘finish level ‘ to make flashing sit as flush as possible to wall . Flashing will be visible - but it is just a black metal strip !

 

Chipping can’t go into edpm because 75mm of concrete is on top . But no sand , mot1 - concrete all the way !!

 

your help is + 1001 ?

[Tennentslager]

3. EPDM TO EPDM.

Splice tape good.

Contact adhesive also good with a 3" overlap and nice tidy (no ripples) contact.

In this weather it should be fine, the rubber is soft and malleable. Take your time and press it all tight together. Roller is good but ONLY on a flat surface, otherwise you'll stress the rubber at high points.

Go poster!

[Pocster]

10 minutes ago, Tennentslager said:

3. EPDM TO EPDM.

Splice tape good.

Contact adhesive also good with a 3" overlap and nice tidy (no ripples) contact.

In this weather it should be fine, the rubber is soft and malleable. Take your time and press it all tight together. Roller is good but ONLY on a flat surface, otherwise you'll stress the rubber at high points.

Go poster!

Cheers !

So as I’ve got to add edpm ontop edpm that’s on random stone - roller no good ! I will have to edpm from the floor as it’s flat . Then ‘infill’ with that horrible never setting gunk !! ?

Edited June 7, 2018 by pocster

[mvincentd]

Im trying to recall from your earlier posts........maybe I’m wrong but thinking that nice stone wall is sitting directly on top of your basement wall below.  Without seeing a section drawing through that area to know what damp barrier is where in the construction below the Edpm I’m thinking at face value surely that stone wall should have a dpc across its width and the flashing should terminate into (directly under) that dpc.  Even then, what’s happening on your neighbours side where that theoretical dpc would be.....if their yard floods and water sits against the wall, lower than the (theoretical) dpc, that will soak down the stone wall.........what is the route of your tanking for the lower structure?  Surely you need that to ‘meet’ with the edpm ‘seamlessly’.

Also hopefully it’s just my eyes but assuming you’ve cut that channel for flashing level it looks to me as if the fall on the edpm is towards the house not the gate??  Either way, hopefully the edpm against the house is getting flashed too.  Also do I recall your skylights are designed as ‘drive on’...so I guess the upstand height has been planned to leave the glass flush with the height of the finished drive surface?  I’d love to see the drawing of how this is being achieved if this is the case...but maybe I just misunderstood one of your earlier posts about drive on skylights. If they are actually standard skylights, have they all got sufficient upstand to go 150mm above finished drive surface?

[Pocster]

2 hours ago, mvincentd said:

Im trying to recall from your earlier posts........maybe I’m wrong but thinking that nice stone wall is sitting directly on top of your basement wall below.  Without seeing a section drawing through that area to know what damp barrier is where in the construction below the Edpm I’m thinking at face value surely that stone wall should have a dpc across its width and the flashing should terminate into (directly under) that dpc.  Even then, what’s happening on your neighbours side where that theoretical dpc would be.....if their yard floods and water sits against the wall, lower than the (theoretical) dpc, that will soak down the stone wall.........what is the route of your tanking for the lower structure?  Surely you need that to ‘meet’ with the edpm ‘seamlessly’.

Also hopefully it’s just my eyes but assuming you’ve cut that channel for flashing level it looks to me as if the fall on the edpm is towards the house not the gate??  Either way, hopefully the edpm against the house is getting flashed too.  Also do I recall your skylights are designed as ‘drive on’...so I guess the upstand height has been planned to leave the glass flush with the height of the finished drive surface?  I’d love to see the drawing of how this is being achieved if this is the case...but maybe I just misunderstood one of your earlier posts about drive on skylights. If they are actually standard skylights, have they all got sufficient upstand to go 150mm above finished drive surface?

Hey 

 

skylights are just walk on 

yeah that photo does make it look like the fall is towards the house - it’s actually the slightest fall the other way !

The wall ( this was another issue ) actually sits on the external insulation of the below structure .Has a special bracket fixed to the blockwork . So in theory water running down the stone work would run outside the below structure .

I built the wall - no dpc ( oops ) . No neighbour on the other side ; it’s a lane 

The below ground structure blockwork also has plastic sheeting over it ( though of course that could tear and I’d not know ) . Land drain at the base of that 

 

Internally below ground will have newton dimpled membrane on the walls and will lap back over part of the ceiling .

 

Some photos to perhaps make clearer

[Pocster]

The thing is even I can’t remember what’s gone in it ! ?

When *just* 100mm concrete - never had a leak apart from open sky lights ( of course ) and where the concrete pour shrunk back from the steels - so hairline cracks .

Been like that for years ?

So reality suggests it is waterproof as in water above ground runs outside the build . But belts and braces are preferred ....

I

[Pocster]

The skylight upstands are not the correct height !

The glazing was another issue !!!!!!

So ! I tried to be clever and had some firrings made ( didn’t know they were called that ) . I’ll fix these on top the openings and as they are deliberately longer than required can adjust to suit the glazing ; I.e can make flush with final floor 

[mvincentd]

Ok, I’m getting you , so the Newton dimples lap over the top of that concrete ceiling but don’t reach to bond with the edpm, so while water running down the stone wall should be stopped by your (work in progress) flashing, dampness in the stone wall can reach down to behind the dimples....including on top of the dimples that are lapped onto the ceiling, so if it tracked far enough to exceed the lap of the dimples it would be onto the top of the ceiling.

 

Thats how I’m reading it if there are no further damp proof membranes...is that right.

 

In that case it looks to me like technically you are vulnerable, but realistically, it might never happen.  Whether you should be concerned I’m not experienced/qualified to say. Based on what I understand of this though,  If it were my build I’d drop a few quid on a surveyor who specialises in remediation of damp problems having a look, or get your building control guy (if he’s the helpful type) to apply his brain to it.

 

Regarding “can make flush with final floor”...I believe your average walk on skylights that APPEAR flush only do so because the paving surrounding them is on pedestals raising them above a clear drainage floor that is somewhat below the top of the upstand on which the skylight is sitting. If your slabs are sitting on a mortar bed right up to edge of skylight I think you’ll have a problem.