Make an appointment Call now

Roofs: Construction, pollution and solutions

Sagging roofs are a common issue that can arise from weak joists, heavy roof tiles, or structural modifications, posing a risk to the integrity of your home. Discover the key signs to watch for, preventive measures to take, and when to call in professional help to ensure your roof remains strong and stable.

Sagging (sagging) in the roof structure may be visible. This can have several causes, including a problem with the underlying joists or structure. Joists may be too weak or may have been modified, causing a weakening. It's also possible that the roof tiles are too heavy for the structure, or that other structural changes have been made, such as a dormer or skylight. As soon as the sagging increases, improvements can be made to the ridge beam, purlins, trusses, or other reinforcements on the inside of the roof surface.

homekeur-doorzakken-dakbeschot.png

In older homes, some saturation related to the year the home was built is not uncommon.

A kink may be noticeable on the underside of the roof. This is often caused by moisture rising or splashing up from the gutter, which has long-term affected the chipboard roof sheathing or the structure, causing it to weaken. The underside of the roof sheathing is likely weakened and sagging. This isn't necessarily a major problem, but it should be monitored.

homekeur-spaanplaat-dakbeschot-doorzakken.png
  • If this worsens or accelerates, the situation must be reassessed. Call in a professional.
  • If necessary, small knee walls can be placed in the attic at any time to strengthen and thus stabilize the roof surface.
  • Average cost of a new roof.

Pollution or water on the roof

  • Contamination in any form must of course always be removed from every roof surface.
  • Clean water on a roof is usually not a problem. However, it's a different story if a layer of water remains over the entire roof, or if a large puddle of standing water remains on the roof and the water can't drain away. To prevent roof damage, it's wise to properly drain the water by installing downpipes or ensuring a good slope.
    • Check that the drains are not blocked by moss, leaves or twigs.
    • If water remains in one spot and can't drain away, it can damage and weaken the roof structure.
    • With water on a roof, there is a chance that this water pool will attract animals and that plants will eventually start growing in it.
homekeur-vervuiling-dakbedekking.png

Would you like to make an appointment for a building inspection?

The cost of a building inspection (up to 250 m²) is only €489 including VAT. We'll conduct a comprehensive building inspection and you'll receive a building report. Do you have any questions? We're happy to help and can schedule an appointment with an expert inspector right away if you wish!

Recent articles

Een vrouw wijst naar een tablet die een man vasthoudt en een andere man kijkt mee
blog
13 February 2026
Hidden defects in a home
Hidden defects are not uncommon, especially in existing homes. They are often not immediately visible, but can have significant consequences for comfort, safety, and costs. This article explains how hidden defects are assessed and the role of investigation and inspection.
blazen plooien bitumen dak
video
13 February 2026
Common roof detail mistakes: what an inspection reveals
During roof inspections, problems often turn out to be not in the roofing itself, but in the details. In this practical case study, we demonstrate which installation errors are frequently encountered and why these, in particular, pose an increased risk of leaks and damage.
WhatsApp Image 2026-02-12 at 08.51.37
video
12 February 2026
Three Roof Eave Mistakes That Cause Leaks (And Are Often Overlooked)
Roof problems rarely arise suddenly. They usually start with a minor issue. In this inspection, we see how a torn lead flashing, improper installation, and a loose joint can all pose a serious risk. What should you look for—and how can you prevent them?