Blisters and wrinkles are visible changes that need description, not a complete diagnosis. Record their location, pattern and earlier alterations, then have the material, fixing and underlying layers assessed before selecting a repair method.
How should the visible change be described?
Describe whether you see a raised area, fold or apparently loose transition and where it is located. Note whether it is isolated or forms a pattern across a larger surface. Relating it to a seam, edge or penetration makes the location identifiable without immediately suggesting a cause.
Use neutral language if the material is unknown. A dark membrane cannot be assigned a particular composition from colour alone. Retain photographs from different dates where available. A newly noticed wrinkle is not necessarily newly formed, so also record when the roof was last actually observed. This distinction prevents the reporting date from being mistaken for the date the change occurred.
Which relationships belong in the assessment?
The visible layer forms part of an assembly containing a substrate, possible insulation and junctions. Ask which of these have been included in the assessment. A statement about the surface alone may leave important questions unanswered about its relationship with existing layers or earlier repairs.
Have the assessor distinguish the observed feature, a possible explanation and the proposed intervention. Where further investigation is needed to connect those steps, it should be identified explicitly. This explanation does not provide a testing method for occupants. Puncturing, cutting or opening the material yourself can alter the situation and is not a reliable substitute for a professionally bounded investigation.
How should a repair boundary be chosen?
A repair boundary should follow from the finding, not merely from the outline of the visible wrinkle. Ask how the intervention connects to retained material and which existing details it includes. Even when the action is local, the assessment may need to consider a wider surrounding area.
Distinguish temporary action from final repair. A surface measure may serve a different purpose from renewal of several layers. Where alternatives are proposed, compare the same components and uncertainties. The quantity of new material alone does not show whether the cause was sufficiently investigated or the chosen transition properly justified. The proposal should explain the relationship between finding and scope.
What should be kept for later comparison?
Keep an overview retaining seam lines and other recognisable reference points. Add a material description only as far as documents or investigation establish it. Describe earlier work with the level of certainty the record actually supports, rather than assigning a presumed product to an unidentified patch.
After an intervention, connect the work boundary and completed action to the same image sequence. This helps establish whether a later report concerns the treated area or an adjacent one. A maintenance note saying only “roof checked” loses that relationship. Ask for enough concrete information to recognise future changes without having to reconstruct the entire history from disconnected memories.
Worth asking
Frequently asked questions
Should I puncture a blister?
No DIY repair is advised here. Have the feature assessed without changing the assembly yourself.
Does every wrinkle mean a leak?
Its shape alone cannot establish that. Material, location and relationships require assessment.
Must the whole surface be replaced?
That conclusion does not automatically follow from a visible feature. A justified work boundary requires investigation of the actual situation.