Defective roofing works causing internal cracks and popping noises

[Sasharoo22]

Hi all

Just after some advice if anyone can help?

We had poor roofing works done last April(ridge/verge/eaves). All perimeter tiles, including the verges and ridge are loose with a large gap in the felt along the ridge - roofing reports and the council have confirmed this. The insulation is stuffed into the eaves and we have failed Part L.

We are now experiencing a regular popping noise early evening to the early morning plus quite bad cracks to the living room ceiling along the plasterboard lines.

I've researched and can anyone tell me if this is correct?

Roof Defects, Thermal Movement, and Ground-Floor Cracking

• Truss Uplift via Microclimate Destabilisation: Displaced ridge and perimeter tiles allow unrestricted external airflow and moisture into the roof cavity. This creates extreme temperature and humidity differentials between the insulated lower chords and exposed upper chords of the fink trusses, accelerating differential thermal expansion and contraction (truss uplift).
• Diurnal Thermal Ratcheting (Acoustic Popping): The unchecked influx of cold night air through the loose ridge and perimeter tiles causes rapid cooling of the roof cavity from early evening to early morning. This triggers a "stick-slip" friction release (the audible popping/ticking noises) at the timber joints and metal gang-nail plates as the fink trusses contract, proving the structure is undergoing active, daily thermal movement.
• Wind Uplift and Structural Stress Transfer: The loose verge and perimeter tiles allow wind to get underneath the roofline, causing cyclic aerodynamic lift and flexing of the gable-end trusses. Because the bedroom ceiling moves dynamically with the roof, it remains intact, while this mechanical and thermal stress is transferred down the rigid gable cavity wall and released into the ground-floor ceiling framework.
• Hygroscopic Movement and Joist Deflection: Rainwater penetrating the compromised gable verge tracks down the inner skin of the brick cavity wall. This moisture accumulates where the first-floor floor joists are pocketed into the gable wall, leading to localised timber expansion, softening, or minor deflection that manifests as plasterboard cracking in both the gable corner and the middle of the living room ceiling span.
  

  ---

• Relevant Industry References:
• Truss Uplift & Popping: BRE Digest 346 ("Pitched Roofs: Performance and Assessment") and NHBC Standards Chapter 7.2. Covers truss movement, stick-slip noise, and microclimate stability.
• Wind Uplift & Stress: British Standard BS 5534 (Code of Practice for Slating and Tiling) and NHBC Clause 7.2.8 (Gable Restraint). Covers structural stress transfer down the gable wall.
• Water Tracking: BRE Good Building Guide 27 ("Building damp-free cavity walls"). Covers roof-to-cavity water entry and intermediate joist deflection.

Any advice or feedback would be appreciated.

Thanks, Sasharoo

 

[^woody^]

Stay off Google or Ai for a diagnosis! All of those are bordering on theoretical science, not actual real world likelihood.

Instruct a competent, experienced building surveyor to investigate and determine the issues.

Alternatively, if the property had no problems before this poor roofing work, then if the poor work has been identified then surely if it is corrected the issues will be resolved and the damage can bemade good?

Are these popping noises from plastic gutters and facia/soffits?

You can't "fail" Part L unless you are building to specific Part L standards in the first place

 

[Sasharoo22]

Woody

Thanks for your reply.

Yes we know we have to now have a reroof as the repairs are so bad.

The noise sounds like a lump hammer hitting concrete, if that makes sense?

We had over 50% repairs done which triggered local authority involvement.

The ridge has been nailed directly into the truss apex with no brackets and the verges have been cut to span 1 rafter on 600mm gauge truss. No perimeter tiles are fixed, Marley Wessex tiles.

We have had a structural survey but they said they can't really comment on roofs and thermal expansion, although they have said it is thermal cracks.

Just trying to find the right people to look at it.

NFRC have confirmed all repairs are poor.

Thanks, Louise

 

[^woody^]

Thermal cracking can be caused by changes in the structure creating changes in the internal environment, but typically in those instances its making the environment warmer and dryer causing shrinkage - typically after things getting wet, then being repaired then drying out. However its also a phenomenon and can occur at any time due to changes in the seasons or even putting the heating on in a cold winter. Proving a connection of thermal cracking and defects or coincidence can be difficult. Also, such movement tends to be a one-off event, not continuing movement.

The problem you may have is that roofers (eg NFRC members) deal primarily with the roof coverings not the roof structure. So when you get a roofer to look at the roof construction, you have to be sure that they are actually qualified to comment, not just give opinion.

A TRA member may be more able to comment on trussed roofs www.tra.org.uk/

Overall, a competent experienced building surveyor should be able to comment on everything and will/should be able to seek out more specific comment from a relevant other trade or professional. If minded to appoint a surveyor, then be specific in what you require and expect, and categorically state that you do not want a report full of maybe's and could do's or recommending further investigations. You want answers from someone able to give them.

If things were OK before the work, then a start is to understand what was actually done to the roof cover and the roof structure. A trussed roof structure would not be expected to start moving or flexing unless structural members or bracing/brackets have been removed. But the noise you describe is typical of something heating up, moving then springing back (the bang/crack). Blocking eves ventilation with insulation could, potentially create a warmer internal roof void. Typically, the louder, deeper the noise the more likely is related to bigger components, but thats not necessarily bigger movement.

There may be several things to investigate, and you may get others mention things to consider. But I would suggest that this may be a specific issue that may only be resolved by on-site investigation, not online conjecture. There are other threads about strange noises from roof/lofts if you have a search

You should be able to claim the cost of a specialist report back from the firm that caused the issue