CertBox
Gas Engineers Create in CertBox

Flue in Void Risk Assessment (CP43)

A CP43 documents a risk assessment for gas flues passing through voids such as ceiling spaces, floor cavities, or service risers. Where a flue passes through a space that is not readily accessible for visual inspection, the engineer must assess the risk of flue gas leakage into occupied areas. Gas Safe Technical Bulletin TB 008 provides the framework for this assessment.

Gas Safety (Installation and Use) Regulations 1998, Gas Safe Technical Bulletin TB 008Valid: One-off (reassess if installation changes)

No credit card required. Set up in 30 seconds.

Sample CP43 certificate

Sample Flue in Void Risk Assessment (CP43) certificate created with CertBox, showing the professional PDF layout with flue route identification through voids, joint accessibility assessment, risk classification (high, medium, low)

Sample CP43 with fictional data. All personal details shown are fake.

What it covers

  • Flue route identification through voids
  • Joint accessibility assessment
  • Risk classification (high, medium, low)
  • Void ventilation and CO detection recommendations
  • Photographic evidence of flue route
  • Recommended remedial actions

Who needs a CP43?

Gas engineers
Landlords
Property surveyors

Create your CP43 with CertBox

1

Fill in the form

Pick CP43 from the list, fill in the fields on your phone.

2

Compliance checks run

Built-in validation catches missing fields and out-of-range readings.

3

PDF generated instantly

Professional PDF ready to share via secure link or download.

Frequently asked questions about CP43

When is a flue in void risk assessment needed?
A CP43 is needed whenever a gas flue passes through a void (ceiling space, floor cavity, or service riser) where joints are not visible or accessible for inspection. This commonly arises during landlord gas safety checks when the engineer identifies a concealed flue route.
What happens if the risk assessment identifies a high risk?
The engineer should recommend remedial work such as installing an access panel, adding CO detection in the void, or re-routing the flue. In some cases the appliance may be classified At Risk until the void can be inspected or made safe.

Related certificates

Gas Engineers

CP12

A CP12 is the annual gas safety check every UK landlord needs. Learn what it covers, who can issue one, and create compliant CP12s digitally with CertBox.

Gas Engineers

Gas Warning Notice

Create digital gas warning notices for unsafe situations. ID, AR, and NCS classifications with built-in GIUSP compliance checks. Works on any phone.

Gas Engineers

CP26

Create CP26 fumes investigation reports on your phone. CO readings, appliance classification, incident documentation. Professional PDF on site.

Gas Engineers

CP3

Create CP3 chimney and flue commissioning records digitally. BS 5440 compliant, spillage tests, termination checks. PDF on site with CertBox.

Ready to create your CP43?

Free forever. Set up in 30 seconds, no card required.

No credit cardCancel anytimeSet up in 30 seconds

Create your CP43 in minutes