Septic Tank Water Ingress

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In this video we will be looking at what happens when your septic tank is affected by water ingress.

The purpose of a septic tank is one of settlement and separation. This process is most effective when the septic tank is in a state or period of inactivity.

When the foul waste water settles in the septic tank, the solids in the water break down and separate into 3 distinct layers.
As the septic tank collects the waste from the property, less dense waste material floats to the surface to form a scum layer. The more dense waste material sinks to the bottom of the tank, forming sludge. The partially clarified liquor from between the two layers is allowed into the outfall drainage field or soakaway
Septic tanks operate on the basis of hydraulic displacement. This means that the same amount of liquid that enters that tank, causes the same amount of liquid to exit the tank, regardless of the length of time the liquid has been detained in the tank to achieve settlement and separation.

If the structure of the septic tank is compromised by an external force, ground water could be forced into the tank via a breech in the tank wall. The uncontrolled inflow of groundwater causes turbulence of the otherwise quiescent conditions, causing the originally settled matter to go back into suspension and ultimately is discharged into the soakaway.

When the wrong type of waste enters the soakaway system, the solid material contained within the discharge fills the voids in the surrounding soil of the drainage field or soakaway. This cannot be undone and any further treatment of the waste will be prevented as the system has become choked and exhausted.

The soakaway system will continue to fill with the waste from the septic tank and either quickly backs up through the system and into the property, or finds its way to ground level and starts to pool on the surface above the soakaway.

If your septic tank is backing up, or you have noticed waste pooling above the system, call UKDP today on 01628 788 600 or visit our website at to arrange a septic tank investigation.


Rainscreens: 5 Things You Need To Know to Protect your Walls

What is a Rainscreen? How does a Rainscreen prevent moisture problems? Do you need a rainscreen? Take 2 minutes to learn about rainscreens and how they can prevent stucco & other moisture problems. Keep learning at


In a typical rainscreen system the exterior deflects most of the moisture. A gap of at least 1/8″ behind the exterior allows any moisture that penetrated the rainscreen to drain out of the wall. Behind the drainage gap and on top of the sheathing the weather resistive barrier protects against moisture intrusion into the wall system.

Why not just use a weather resistive barrier (WRB)? Without the rainscreen drainage gap you don’t have a rainscreen system. Without the gap capillary action can hold moisture against the WRB, and find its way into imperfections and penetrations in the WRB, including at fasteners. Once water gets behind the WRB it has few opportunities to get out, and creates an environment that promotes mold and rot on the wall assembly. Using a rainscreen drainage product such as Sure Cavity ensures that there is a drainage and ventilation gap so that liquid water can drain out of the wall, preventing moisture related damage.

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Moisture Intrusion (Damp) & Mould Inspection

Here is the video clip from a recent home inspection we did where moisture intrusion and damp conditions were a big problem. The moisture ingress in this case was conducive to mould growth which necessitated the need for further air quality mould testing on that building interior.