Can a joint that is welded by solvent cement be submerged in water?

As long as the joint is set and hardened before then it can be submerged in water.

However it must not be used in fish ponds and must not be used in swimming pools where any pressure from a pump will pass through the system.

Can ABS waste pipes be used externally?

Yes but they must be painted.

Can Air Admittance Valves be used with cesspools or septic tanks?

FloPlast air admittance valves can be used with both a cesspool and a septic tank as long as there is another pipe venting the system between the tank and the air valve. Ideally closer to the tank.

If the system  is not vented and an air valve is installed then this could result in a build up of gasses and potentially an explosion.

Can FloPlast Air Admittance Valves be installed below the flood level of appliances that they are serving?

Yes, 110mm air valves need to be at least 200mm above the highest wet entry point into the stack that they are sitting on.

32mm, 40mm & 50mm air valves need to be branched off at least 100mm higher than the waste pipe carrying the waste water.

Can I fit my AAV to the outside of the building?

FloPlast now manufacture a valve capable of being fitted externally.

Can Polypropylene waste pipes be used externally?

Yes but they must be painted.

Can PVC soil pipes be painted?

Yes, the pipe must be degreased first and then apply 2 coats of any water based gloss paint; the first coat can be thinned.

Can ABS solvent weld waste pipes be connected to Polypropylene?

Yes, use Unicom Compression Waste fittings, similar to those on our trap outlet.

Can PVC-U waste pipes be used externally?

Yes. Painting is not required.

Do any FloPlast Air Admittance Valves have a pressure rating of 10psi (0.7 bar) so that they can be installed with a Saniflo system?

No, FloPlast do not make any air valves that will be suitable for use with a Saniflo system.

Do FloPlast Air Admittance Valves have to be installed vertically?

Yes. All FloPlast AAV’s must be installed vertically with no angle at all.

Do I need to install fire prevention collars when installing a pipe through a wall or floor?

Fire prevention collars are only required when a pipe penetrates through a wall or floor of a neighbouring property, i.e. a block of flats or apartments.

When connecting a pipe through a wall or floor, the use of a fire collar will prevent fire jumps between rooms. The intumescent strip will close the gap and prevent the fire spreading.

Do I need to insulate my AAV?

No, as the operating temperature is -20°C at the lower end insulation is not required.

How do I stop the ‘Gurgling’ effect when I empty my bath?

FloPlast manufacture a range of Air Admittance Valves to overcome this problem. Please refer to our section on Air Admittance Valves within the Soil and Waste pages

How far will 110mm soil pipe push into the fittings?

If the pipe is chamfered then it will push 65mm into the fittings. If it is not chamfered and cut to a straight line then it will push approx 60mm into the fittings

How far will the flexible WC connector (SP106) expand?

The connector will expand from 180mm to 300mm, this is the distance when installed. The overall length of the connector is 385mm and when fully retracted the overall length is 260mm.

How far will the Flexi-Tube (FT32/FT40) extend?

The Flexi-Tubes will be 320mm fully retracted and will extend to 500mm when fully extended.

How far will the TP47T/ TB47T extend?

Both of the telescopic traps will extend from 37mm to 120mm.

How long do you need to leave the Solvent Cement to dry?

When cementing two joints together you will have between one and two minutes before the cement starts to set and you will struggle to move the joints.

The joint will then need to be left for 2-3 hours for short discharges or for a continuous discharge 24 hours.

I am installing a new w.c. pan and the existing Pipe is at a different height to the new outlet.

Use FloPlast SP102 Offset WC Connector, or SP106 Flexible WC Connector.

I am trying to connect pipes that are at a Non standard angle, how do I do this?

FloPlast have 0-90º Adjustable bends in 32mm and 40mm ‘UNICOM’, and 110mm in above ground soil and Underground Drainage.

I need to connect to an existing waste pipe but I am not sure of the size.


If I need to fit an old copper or lead pipe what fitting should I use?

FloPlast offer both compression waste fittings, which are multi fit and Flexi-flo adaptors that operate with a screw-on jubilee clip.

In what situation would you use a anti vac bottle trap?

The anti vac bottle traps are used to stop the gurgling between a bath and a wash hand basin.

In what situations would I use a 32mm, 40mm or 50mm Air Admittance Valve?

If a 32mm waste pipe is longer than 1.5 mtrs, a 40mm pipe 3 mtrs, and a 50mm pipe 4 mtrs, then the options are to increase the pipe size to the next size, and/or install an air admittance valve.

A mini air valve can also be added where there are several appliances in close proximity, this will help reduce the possibility of induced siphonage sucking the water from the traps.

What ancillaries can be used with drinking (potable) water?

The ancillaries that can be used with drinking water are SL50 (50g lubricant gel), SG100 (100g Silicone Grease) & SG800 (800g Lubricant Gel)

What are the measurements of the 110mm Air Admittance Valves?

AF110/ AX110 measurements are:
Across the top – 148mm
Overall Height – 122mm
Height when installed (Top of the soil pipe to top of AAV) – 72mm

AV110 measurements are:
Across the top – 148mm
Overall Height – 115mm
Height when installed (Top of the soil pipe to the top of the AAV) – 65mm

What are the operating parameters of FloPlast Air Admittance Valves?

FloPlast’s Air Admittance Valves have been tested in accordance with BS EN 12380 and been designated as A1 – this means that the products have an operating window of -20° C to 60°C.

What bend should be used at the base of 110m soil pipe?

A long radius 87 ½o Rest bend or 2 x 45 o bends, minimum radius 200mm.

What clipping distances should be used for 110m soil pipes?

Vertical pipe sockets should be anchored with socket clip and a pipe clips fitted at 1.8 metres centres maximum Horizontal runs should be anchored at sockets and pipe clips at 1.0 metre centres. Please refer to our Soil & Waste Brochure.

What fire ratings do fire collars have?

FloPlast’s fire collars have a four hour rating.

What fittings do I need to fit my waste Pipe to my soil pipe?

FloPlast produce a range of boss pipes and adaptors. Please refer to our section on bosses and adaptors.
Please refer to our Soil and Waste Brochure.

What is the air flow of the FloPlast Air Admittance Valves?

FloPlast air admittance valves are tested to flow rate and not by pressure:

The 32mm & 40mm air flow rate is 6.5 litres per second.
The 110mm push fit & solvent internal air valves air flow rates are 43 litres per second
The 110mm push fit external air valves air flow rate is 34.7 litres per second

What is the benefit in using Soil Manifolds?

The FloPlast manifold has versatile inlets for the multi connection of up to four connections from 30/40 and 50mm waste pipes in both.

What is the best trap to use?

The most common traps would be the P or S traps for under a sink, or bottle/pedestal traps for basins.

When installing appliances please refer to our Washing machine or combination traps.

What is the compatibility with other manufactures?

All 32mm, 40mm and 110mm systems are compatible with all other manufactures and most 50mm systems are compatible with most other manufactures.

What is the conversion from Imperial to metric pipe sizes?

Nominal imperial pipe size Nominal metric pipe size
1 1/4" 32mm
1 1/2" 40mm
2" 50mm
3" 82.4mm
4" 110mm
6" 160mm


What is the suitability of the Flexiflo couplings with certain chemicals?

Please refer to our Flexiflo Connectors section and download our Chemical Resistance Guide.

What materials are used to make the products?

Cellular Fascia, Soffit and Cladding – PVCUe – Poly Vinyl Chloride expanded.
Unicom Compression, Pushfit Waste and some elements of both Above Ground and Underground
Drainage – Polypropylene.
ABS (Solvent Waste) – Acrylonitrile Butadiene Styrene.
Above Ground, Underground Drainage and Rainwater – PVC-U – Unplasticised Polyvinyl Chloride.

What size hole needs to be cut out of the soil fittings for the boss adaptors to fit?

The hole size that needs to be cut out is 54mm.

What size pipe will the weather slate (SP320) fit onto?

The weather slate comes with a rubber cone that can be cut to size and will fit onto pipe sizes between 55mm and 170mm.

What size waste pipe do I need to use?

32mm Pipe is used for wash hand basins in the bathroom or cloakroom & 40mm pipe is used for every other appliance.

What temperatures can the Air Admittance Valves work to?

In accordance with BS EN 12380 FloPlast air admittance valves will work between temperatures of -20°C to + 60°C

With the air valves working at temperatures of -20°C there is also no need of insulation.

What temperatures can the Overflow system withstand?

The pipe will start to soften at 75°c but if it is a constant run then it will start to soften at 55°c.

What traps do I use for wash hand basins?

For wash hand basins you can use a P trap, S trap, Bottle trap or a Pedestal trap

What water temperature can be discharged through soil and waste pipes?

All FloPlast products are tested to the relevant British Standards at 93°C – 95°C. This is an intermittent hot and cold cycle test. Water under continuous discharge should not be hotter than 70°C – 75°C. Water at higher temperatures should be restricted to 2 minutes.

Where would I use a Pedestal Trap?

FloPlast’s pedestal trap new slim line design, fits neatly behind the basin pedestal.

Which waste system (polypropylene or ABS) should I use?

FloPlast’s pedestal trap new slim line design, fits neatly behind the basin pedestal.

Which waste system (polypropylene or ABS) should I use?

Below are the advantages and disadvantages


Rigid joints
Suitable for external use
Cannot be separated
Easy assembly
Protection from daylight not required

Generally more expensive than Polypropylene systems
Less resistant to impacts than the PP
Temperature resistance is not as high PP
Not as resistant to chemicals as PP


Simple assembly
Cheaper than solvent weld system
Can be separated
Expansion provided to longer waste runs
Flexible joints
Greater resistance to impacts than PVC-U
Capable of withstanding higher temperatures than PVC-U systems

Unable to be used externally without protection from U.V. rays
Support required for joints