Just wondering about the type of glue that should be used on the plumbing fittings with a charged system storm water to the rain Tank , pressurised or non pressurised , my understanding is that they are two colours blue and green being the pressurised glue ?
If anybody could shed any light on it
Thanks in advance
Storm water
Page 1 of 4
It is solvent cement, not glue. The solvent 'melt' then melds the two surfaces.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
It is solvent cement, not glue. The solvent 'melt' then melds the two surfaces.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
Just my English heritage calling it glue !
Thanks You appreciate your time in replying
It is solvent cement, not glue. The solvent 'melt' then melds the two surfaces.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
Water only exerts a pressure of 9.8 kPa per metre of head, either solvent is ok but I always use clear to eliminate the possibility of any inadvertent aesthetic issues. It is important to use primer to remove the glaze and any oils from the surfaces to be treated.
Charged systems have problems with sediment build up etc but this can be overcome with some simple and inexpensive design tricks that will reduce maintenance and improve the water quality.
Also, if you have first flush diverters, don't have them uselessly fitted to the top of the vertical riser. Total waste of money and yield. They should only be fitted at the downpipes.
Just my English heritage calling it glue !
Thanks You appreciate your time in replying
This is on my list next time we see ss
H1 soil , pipes laid in uncompacted fill
Are those pipes for the tank?
Yes all in made up ground , no compaction.
will be interesting to see if they use a flexible connector to allow for movment
will be interesting to see if they use a flexible connector to allow for movment
One pipe (I assume) is the overflow and the other is a wet system pipe, do you know how many downpipes the wet system pipe services?
It looks like you are having a single slimline tank.
If you are interested, I'll post as to what to look out for with wet systems and common installation design mistakes. Hopefully your input and their cooperation will help you avoid the usual problems.
It looks like you are having a single slimline tank.
If you are interested, I'll post as to what to look out for with wet systems and common installation design mistakes. Hopefully your input and their cooperation will help you avoid the usual problems.
We have another set the other side of the tank base picking up down pipes from other side of house
425sqM of roof with 12 down pipes ( 90mm )
It’s a 3500 ltr water tank
425sqM of roof with 12 down pipes ( 90mm )
It’s a 3500 ltr water tank
We have another set the other side of the tank base picking up down pipes from other side of house
425sqM of roof with 12 down pipes ( 90mm )
It’s a 3500 ltr water tank
425sqM of roof with 12 down pipes ( 90mm )
It’s a 3500 ltr water tank
One pipe (I assume) is the overflow and the other is a wet system pipe, do you know how many downpipes the wet system pipe services?
It looks like you are having a single slimline tank.
If you are interested, I'll post as to what to look out for with wet systems and common installation design mistakes. Hopefully your input and their cooperation will help you avoid the usual problems.
It looks like you are having a single slimline tank.
If you are interested, I'll post as to what to look out for with wet systems and common installation design mistakes. Hopefully your input and their cooperation will help you avoid the usual problems.
Thanks that would be great
Ok, two vertical risers and two overflow pipes in total. I will assume that all 12 downpipes are being diverted to the tank but if not, you will be able to work back from the information below. I’ll only address the wet system in this post.
Water tank overflow.
When downpipes are diverted to a tank that overflows to a stormwater system, the tank becomes part of the stormwater 'loop' and the wet system pipes and overflow(s) must be hydraulically calculated for compliance to ensure that the wet system has an adequate hydraulic head and that the overflow pipe(s) discharge capacity will prevent the tank overtopping during a major storm event.
Eaves gutter and downpipe compliance is based on your region's 1:20 Average Recurrence Interval (ARI) and your region’s 1:20 ARI is 150mm/hr, based on an average rainfall intensity of 2.5 mm/min over a 5 minute period. The ARI determines the maximum roof areas that can serve various combinations of eaves gutter and downpipe sizes.
In a nutshell, your roof area of 425 sq m would collect 425 x 2.5 = 1,062.5 L of water per minute on average over a 5 minute rain intensity period during a 1:20 ARI.
Roof drainage compliance also factors the roof slope to allow for wind driven rain and this should also be factored for the wet system pipe size and head but I won't go into that here except to say that a standard 22.5 degree roof pitch has an area multiplier of 1.21. When more rain falls on the weather side of the house than on the rain shadow side, you can see the need for these calculations to determine the correct stormwater pipe sizes.
EDITED: For some reason, I wrote that a 22.5 degree roof slope has a compliance multiplier of 1.23 to allow for wind driven rain, I have corrected it to 1.21.
Overflow pipes exiting from a tank's horizontal orifice are subject to Torricelli's Law when calculating the discharge rate and if your overflow pipes are 90mm and fitted to the top of the slimline tank's side as most are, the overflow will have very little mitigation capacity. The mosquito proof overflow mesh also has an open area of about 55% which acts as a flow restriction but round wire has a bell mouthing effect and so the restriction is not as great as one would possibly suspect but there is a restriction nevertheless.
AS/NZS 3500.3 Plumbing and Drainage, Section 8, Water Storage Tanks, Figure 8.2 gives the discharge rate for various size horizontal outlets on storage tanks at various heights over the invert (bottom of pipe). Unfortunately the 90mm pipe is not listed (a SN2 90mm pvc stormwater pipe has an internal diameter of 86.2mm) on the chart but a range of pipes between 40mm and 200mm are listed but with 90mm of water above the invert, a (DN) 90mm pvc stormwater pipe would flow at about 190 lpm...but this is an unmeshed pipe!
Summary: Two (DN) 90mm overflows will not cope with the inflow from your total roof area during heavy rain that is even less that a 1:20 ARI. Of interest, neither would two 100mm overflow pipes.
Post rain, a fine organic film will float on the water surface and eventually settle to the bottom but if the tank is full when it rains within the next several days, the organic film will pass through the overflow mesh but it can also adhere to the mesh. In time, this build up will severely restrict the oulet's flow capacity. To clean the mesh, you need to ensure that maintenance access can be gained by removing the tank’s top meshed inlet but many slimline tanks are not optioned to enable this.
BELOW: Blocked overflow mesh.
A good leaf diverter should be fitted to the top of any downpipe servicing a wet system pipe to prevent organic matter entering and fouling the wet system as well as preventing mosquitoes breeding. From egg to adult mosquito takes about 12 days and a raft of eggs can number up to 400. The best leaf diverter currently available is the ICON “Leaf and Debris Controller”. Many northern areas mandate leaf diverters on wet systems but I don’t know if your area is one of them.
The wet system pipe outlets above the top of the tank should also have flap valves fitted to prevent mosquito ingress.
Water tank overflow.
When downpipes are diverted to a tank that overflows to a stormwater system, the tank becomes part of the stormwater 'loop' and the wet system pipes and overflow(s) must be hydraulically calculated for compliance to ensure that the wet system has an adequate hydraulic head and that the overflow pipe(s) discharge capacity will prevent the tank overtopping during a major storm event.
Eaves gutter and downpipe compliance is based on your region's 1:20 Average Recurrence Interval (ARI) and your region’s 1:20 ARI is 150mm/hr, based on an average rainfall intensity of 2.5 mm/min over a 5 minute period. The ARI determines the maximum roof areas that can serve various combinations of eaves gutter and downpipe sizes.
In a nutshell, your roof area of 425 sq m would collect 425 x 2.5 = 1,062.5 L of water per minute on average over a 5 minute rain intensity period during a 1:20 ARI.
Roof drainage compliance also factors the roof slope to allow for wind driven rain and this should also be factored for the wet system pipe size and head but I won't go into that here except to say that a standard 22.5 degree roof pitch has an area multiplier of 1.21. When more rain falls on the weather side of the house than on the rain shadow side, you can see the need for these calculations to determine the correct stormwater pipe sizes.
EDITED: For some reason, I wrote that a 22.5 degree roof slope has a compliance multiplier of 1.23 to allow for wind driven rain, I have corrected it to 1.21.
Overflow pipes exiting from a tank's horizontal orifice are subject to Torricelli's Law when calculating the discharge rate and if your overflow pipes are 90mm and fitted to the top of the slimline tank's side as most are, the overflow will have very little mitigation capacity. The mosquito proof overflow mesh also has an open area of about 55% which acts as a flow restriction but round wire has a bell mouthing effect and so the restriction is not as great as one would possibly suspect but there is a restriction nevertheless.
AS/NZS 3500.3 Plumbing and Drainage, Section 8, Water Storage Tanks, Figure 8.2 gives the discharge rate for various size horizontal outlets on storage tanks at various heights over the invert (bottom of pipe). Unfortunately the 90mm pipe is not listed (a SN2 90mm pvc stormwater pipe has an internal diameter of 86.2mm) on the chart but a range of pipes between 40mm and 200mm are listed but with 90mm of water above the invert, a (DN) 90mm pvc stormwater pipe would flow at about 190 lpm...but this is an unmeshed pipe!
Summary: Two (DN) 90mm overflows will not cope with the inflow from your total roof area during heavy rain that is even less that a 1:20 ARI. Of interest, neither would two 100mm overflow pipes.
Post rain, a fine organic film will float on the water surface and eventually settle to the bottom but if the tank is full when it rains within the next several days, the organic film will pass through the overflow mesh but it can also adhere to the mesh. In time, this build up will severely restrict the oulet's flow capacity. To clean the mesh, you need to ensure that maintenance access can be gained by removing the tank’s top meshed inlet but many slimline tanks are not optioned to enable this.
BELOW: Blocked overflow mesh.
A good leaf diverter should be fitted to the top of any downpipe servicing a wet system pipe to prevent organic matter entering and fouling the wet system as well as preventing mosquitoes breeding. From egg to adult mosquito takes about 12 days and a raft of eggs can number up to 400. The best leaf diverter currently available is the ICON “Leaf and Debris Controller”. Many northern areas mandate leaf diverters on wet systems but I don’t know if your area is one of them.
The wet system pipe outlets above the top of the tank should also have flap valves fitted to prevent mosquito ingress.
That’s great info thanks
Ok, two vertical risers and two overflow pipes in total. I will assume that all 12 downpipes are being diverted to the tank but if not, you will be able to work back from the information below. I’ll only address the wet system in this post.
Water tank overflow.
When downpipes are diverted to a tank that overflows to a stormwater system, the tank becomes part of the stormwater 'loop' and the wet system pipes and overflow(s) must be hydraulically calculated for compliance to ensure that the wet system has an adequate hydraulic head and that the overflow pipe(s) discharge capacity will prevent the tank overtopping during a major storm event.
Eaves gutter and downpipe compliance is based on your region's 1:20 Average Recurrence Interval (ARI) and your region’s 1:20 ARI is 150mm/hr, based on an average rainfall intensity of 2.5 mm/min over a 5 minute period. The ARI determines the maximum roof areas that can serve various combinations of eaves gutter and downpipe sizes.
In a nutshell, your roof area of 425 sq m would collect 425 x 2.5 = 1,062.5 L of water per minute on average over a 5 minute rain intensity period during a 1:20 ARI.
Roof drainage compliance also factors the roof slope to allow for wind driven rain and this should also be factored for the wet system pipe size and head but I won't go into that here except to say that a standard 22.5 degree roof pitch has an area multiplier of 1.23. When more rain falls on the weather side of the house than on the rain shadow side, you can see the need for these calculations to determine the correct stormwater pipe sizes.
Overflow pipes exiting from a tank's horizontal orifice are subject to Torricelli's Law when calculating the discharge rate and if your overflow pipes are 90mm and fitted to the top of the slimline tank's side as most are, the overflow will have very little mitigation capacity. The mosquito proof overflow mesh also has an open area of about 55% which acts as a flow restriction but round wire has a bell mouthing effect and so the restriction is not as great as one would possibly suspect but there is a restriction nevertheless.
AS/NZS 3500.3 Plumbing and Drainage, Section 8, Water Storage Tanks, Figure 8.2 gives the discharge rate for various size horizontal outlets on storage tanks at various heights over the invert (bottom of pipe). Unfortunately the 90mm pipe is not listed (a SN2 90mm pvc stormwater pipe has an internal diameter of 86.2mm) on the chart but a range of pipes between 40mm and 200mm are listed but with 90mm of water above the invert, a (DN) 90mm pvc stormwater pipe would flow at about 190 lpm...but this is an unmeshed pipe!
Summary: Two (DN) 90mm overflows will not cope with the inflow from your total roof area during heavy rain that is even less that a 1:20 ARI. Of interest, neither would two 100mm overflow pipes.
Post rain, a fine organic film will float on the water surface and eventually settle to the bottom but if the tank is full when it rains within the next several days, the organic film will pass through the overflow mesh but it can also adhere to the mesh. In time, this build up will severely restrict the oulet's flow capacity. To clean the mesh, you need to ensure that maintenance access can be gained by removing the tank’s top meshed inlet but many slimline tanks are not optioned to enable this.
BELOW: Blocked overflow mesh.
A good leaf diverter should be fitted to the top of any downpipe servicing a wet system pipe to prevent organic matter entering and fouling the wet system as well as preventing mosquitoes breeding. From egg to adult mosquito takes about 12 days and a raft of eggs can number up to 400. The best leaf diverter currently available is the ICON “Leaf and Debris Controller”. Many northern areas mandate leaf diverters on wet systems but I don’t know if your area is one of them.
The wet system pipe outlets above the top of the tank should also have flap valves fitted to prevent mosquito ingress.
Water tank overflow.
When downpipes are diverted to a tank that overflows to a stormwater system, the tank becomes part of the stormwater 'loop' and the wet system pipes and overflow(s) must be hydraulically calculated for compliance to ensure that the wet system has an adequate hydraulic head and that the overflow pipe(s) discharge capacity will prevent the tank overtopping during a major storm event.
Eaves gutter and downpipe compliance is based on your region's 1:20 Average Recurrence Interval (ARI) and your region’s 1:20 ARI is 150mm/hr, based on an average rainfall intensity of 2.5 mm/min over a 5 minute period. The ARI determines the maximum roof areas that can serve various combinations of eaves gutter and downpipe sizes.
In a nutshell, your roof area of 425 sq m would collect 425 x 2.5 = 1,062.5 L of water per minute on average over a 5 minute rain intensity period during a 1:20 ARI.
Roof drainage compliance also factors the roof slope to allow for wind driven rain and this should also be factored for the wet system pipe size and head but I won't go into that here except to say that a standard 22.5 degree roof pitch has an area multiplier of 1.23. When more rain falls on the weather side of the house than on the rain shadow side, you can see the need for these calculations to determine the correct stormwater pipe sizes.
Overflow pipes exiting from a tank's horizontal orifice are subject to Torricelli's Law when calculating the discharge rate and if your overflow pipes are 90mm and fitted to the top of the slimline tank's side as most are, the overflow will have very little mitigation capacity. The mosquito proof overflow mesh also has an open area of about 55% which acts as a flow restriction but round wire has a bell mouthing effect and so the restriction is not as great as one would possibly suspect but there is a restriction nevertheless.
AS/NZS 3500.3 Plumbing and Drainage, Section 8, Water Storage Tanks, Figure 8.2 gives the discharge rate for various size horizontal outlets on storage tanks at various heights over the invert (bottom of pipe). Unfortunately the 90mm pipe is not listed (a SN2 90mm pvc stormwater pipe has an internal diameter of 86.2mm) on the chart but a range of pipes between 40mm and 200mm are listed but with 90mm of water above the invert, a (DN) 90mm pvc stormwater pipe would flow at about 190 lpm...but this is an unmeshed pipe!
Summary: Two (DN) 90mm overflows will not cope with the inflow from your total roof area during heavy rain that is even less that a 1:20 ARI. Of interest, neither would two 100mm overflow pipes.
Post rain, a fine organic film will float on the water surface and eventually settle to the bottom but if the tank is full when it rains within the next several days, the organic film will pass through the overflow mesh but it can also adhere to the mesh. In time, this build up will severely restrict the oulet's flow capacity. To clean the mesh, you need to ensure that maintenance access can be gained by removing the tank’s top meshed inlet but many slimline tanks are not optioned to enable this.
BELOW: Blocked overflow mesh.
A good leaf diverter should be fitted to the top of any downpipe servicing a wet system pipe to prevent organic matter entering and fouling the wet system as well as preventing mosquitoes breeding. From egg to adult mosquito takes about 12 days and a raft of eggs can number up to 400. The best leaf diverter currently available is the ICON “Leaf and Debris Controller”. Many northern areas mandate leaf diverters on wet systems but I don’t know if your area is one of them.
The wet system pipe outlets above the top of the tank should also have flap valves fitted to prevent mosquito ingress.
Just looked at my photos There are 2 pipes into tank and 1 outlet
They can't be diverting all 12 downpipes surely!
EDIT 19 February 2020:
I am still gobsmacked by this act of abject stupidity and wonder just how many 'professionals' have given their 'seal of approval' and how many other properties have similar incompetent systems.
EDIT 19 February 2020:
I am still gobsmacked by this act of abject stupidity and wonder just how many 'professionals' have given their 'seal of approval' and how many other properties have similar incompetent systems.
They can't be diverting all 12 downpipes surely!
If the overflow is at the end opposite the inflow, there won't be a way to access the overflow mesh for cleaning unless you take the pipe off (or if the tank has an extra top meshed inlet).
If the overflow is at the end opposite the inflow, there won't be a way to access the overflow mesh for cleaning unless you take the pipe off (or if the tank has an extra top meshed inlet).
Yes all 12 into tank !
Will be speaking with certifier , our SS is a waste of time hasn’t any idea in the NCC / BCA, just one thing after another at the moment 😔
OMG!!!
The plumber has no idea either.
I am stunned!
The plumber has no idea either.
I am stunned!
OMG!!!
The plumber has no idea either.
I am stunned!
The plumber has no idea either.
I am stunned!
Will keep you posted , thanks for your help
Just checked on the storm water plan as stamped by local council and it shows the 2 lines from both sides of the house into tank and a single pipe from tank to easement at front of block (Storm ditch)
They are clueless and this ain't rocket science.
Does it say who did the stormwater plan?
I have also assumed that the subsurface pipes are 90mm, I would have recommended 100mm DWV with regard to the pipe capacity and the soil classification.
A 90mm pvc SN2 stormwater pipe has an internal diameter of 86.2 mm which gives a volume of 5.84 litres per metre and a velocity of 1 metre per second gives 350 litres per minute. If the pipes used are 90mm pvc stormwater, the velocity of water from your roof through a single pipe during a 1:20 ARI would exceed 3 metres per second!!! At this velocity, the pipe would be operating under sub atmospheric pressure.
A 100mm DWV pvc pipe has an internal diameter of 104mm which gives a volume of 8.5 litres per metre and a flow rate of 510 litres per minute at a velocity of 1 metre per second. Draining your roof during a 1:20 ARI would require the velocity to exceed 2 metres per second.
AS/NZS 3500.3 5.4.11.2 Design Procedure states.....
"The general method for designing a pipe drain for a stormwater drain shall be as follows:
(In part) ..."the full-pipe velocity in the outlet pipe is recommended not to exceed 1.5 m/s and shall not exceed 2.0 m/s."
Regardless, it is a moot point because there is no way that a water tank's 90mm meshed overflow orifice will discharge at anywhere near the required volume which is nearly 18 litres per second to prevent the tank overtopping!
Does it say who did the stormwater plan?
I have also assumed that the subsurface pipes are 90mm, I would have recommended 100mm DWV with regard to the pipe capacity and the soil classification.
A 90mm pvc SN2 stormwater pipe has an internal diameter of 86.2 mm which gives a volume of 5.84 litres per metre and a velocity of 1 metre per second gives 350 litres per minute. If the pipes used are 90mm pvc stormwater, the velocity of water from your roof through a single pipe during a 1:20 ARI would exceed 3 metres per second!!! At this velocity, the pipe would be operating under sub atmospheric pressure.
A 100mm DWV pvc pipe has an internal diameter of 104mm which gives a volume of 8.5 litres per metre and a flow rate of 510 litres per minute at a velocity of 1 metre per second. Draining your roof during a 1:20 ARI would require the velocity to exceed 2 metres per second.
AS/NZS 3500.3 5.4.11.2 Design Procedure states.....
"The general method for designing a pipe drain for a stormwater drain shall be as follows:
(In part) ..."the full-pipe velocity in the outlet pipe is recommended not to exceed 1.5 m/s and shall not exceed 2.0 m/s."
Regardless, it is a moot point because there is no way that a water tank's 90mm meshed overflow orifice will discharge at anywhere near the required volume which is nearly 18 litres per second to prevent the tank overtopping!
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