Soil-Stack Compliance Inspection

Job ID: 40390101

Budget: £250 – £750 GBP

1. Objective of Instruction
To obtain an independent, chartered‑level technical assessment of the soil‑stack installation serving Flat 32, including its offset configuration, ventilation provisions, and compliance with relevant standards, specifically:

Approved Document H (Drainage & Waste Disposal)

BS EN 12056‑2 (Gravity drainage systems inside buildings)

CIPHE Soil & Waste Design Guide

Manufacturer installation requirements (where applicable)

The assessment should confirm or deny compliance and identify any design, installation, or performance defects.

2. Scope of Work Required
A. Physical Inspection
Inspect the soil‑stack riser section accessible from Flat 32.

Identify all offsets, changes in direction, branch connections, and pipe gradients.

Confirm pipe material, joint types, and workmanship quality.

Assess whether the installation matches typical design expectations for a multi‑storey stack.

B. Ventilation Assessment
Determine whether the stack is vented, partially vented, or unvented.

Assess whether the offset configuration requires:

Primary venting,

Secondary venting, or

Relief venting
under BS EN 12056‑2.

Identify any risk of:

self‑siphonage

induced siphonage

back‑pressure

air‑admittance valve inadequacy

hydraulic overload during peak discharge

C. Compliance Review
Provide a formal opinion on compliance with:

Approved Document H (Sections on soil stacks, ventilation, offsets, and branch connections)

BS EN 12056‑2 (Clauses relating to stack design, offsets, venting, and flow capacity)

Good practice guidance (CIPHE, manufacturer standards)

D. Defect Identification
Identify any of the following:

Incorrect offset design

Missing or inadequate ventilation

Poor workmanship

Incorrect pipe sizing

Non‑compliant couplings or fittings

Evidence of long‑term leakage or stress on the system

Any installation features that could cause repeated leaks

E. Reporting Requirements
Provide a written report including:

Photographs and annotated diagrams

Description of the stack configuration

Ventilation analysis

Compliance assessment

Identified defects

Recommended remedial actions

Whether the issues indicate localised failure or potential systemic design issues

3. Evidence Available for Review
I can provide the following:

Polygon contamination and moisture report (with photos and video)

Xtra Maintenance surveyor report (pending today)

Photographs and videos of the riser and pipework

Contractor observations from:

Biocraft

TL Plumbers

Whites of Windsor

Sedgwick

Polygon

Evidence of historic staining, mould, and repeated leaks

4. Access
Full access to the riser opening within Flat 32 can be arranged.
Further opening‑up can be authorised if required.

5. Deliverables
Formal technical report suitable for:

Freeholder

Managing agent

Building Control

Building Safety Regulator

Insurer

Legal review (if required)