This article explores whether roof felt should go into guttering, how it works, and what are its pros and cons.
Should Roof Felt Go into Guttering?
Roofing felt should extend into the gutter overlap by 50-150 mm to provide a weather-tight seal and allow water to drain safely from under the tiles.
However, debris should be prevented from entering at this point.
Overall, it is standard and recommended practice for roof felt to integrate with the guttering system.
Key Points
- Roof felt should overlap with the gutter to seal and drain water
- 50-150 mm overlap is typical
- Prevent debris buildup where felt enters the gutter
Our Opinion
In our experience as roofing experts, integrating roof felt with the guttering system by lapping it into the gutter is important for proper drainage and weatherproofing.
This method ensures water flows from under the tiles safely into the gutter.
However, care should be taken to minimize debris accumulation at the overlap.
Should the Roof Go into Guttering? The Answer
Whether or not roof felt should extend into the gutter is a common question for homeowners. The short answer is yes, it is normal and recommended for roofing underlay to slightly overlap with the gutter. Here’s a more in-depth look at why:
- Extending the roofing underlay into the gutter helps prevent water from seeping under the roof tiles or slates. This provides an extra barrier so moisture doesn’t penetrate the roof deck.
- It is standard building practice for the roofing felt to overhang about 50mm into the gutter. This overhang acts as a secondary barrier even if some tiles become cracked or damaged.
- Without an overhang, there would be a vulnerable gap where water could infiltrate where the roofing meets the gutter. Dripping water could damage fascia boards.
- The roof underlay serves as a temporary water barrier until the tiles are installed. Overhanging into the gutter maintains that protection.
- Most roofing underlay materials are designed to handle some moisture. Extending into the gutter won’t significantly damage modern felts or membranes.
- Any debris from the roofing underlay will be washed into the downpipe. Make sure the downpipe has a mesh cover to catch debris.
The key is not to drape too much felt into gutters. About 50 mm is sufficient. The bottom edge may get wet but quality roofing underlay is designed for that. Therefore, extending it into the gutter is good practice for effective weather protection.
Sarking Felt Explained
Sarking felt is a type of breather membrane used in roofing. It is an alternative to standard roofing underlay that offers additional benefits:
- Sarking felt is water resistant but vapour permeable. This allows any moisture under the tiles to evaporate through the membrane while still providing a water barrier.
- The added breathability helps prevent condensation from building up under the roof covering. This reduces the risk of rot and mould.
- High-quality sarking felts are tear-resistant and durable. They maintain their performance over time.
- Sarking provides a secondary line of defence even if some tiles become damaged or cracked.
- The membrane helps stabilise the temperature under the roof tiles. This can reduce heat loss in winter and overheating in summer.
- Sarking felt acts as a temporary roof covering while tiles are installed. It keeps the roof watertight.
- Some sarking brands are reinforced with a mesh or grid for increased strength and stability.
- Unlike roofing felt, sarking extends right to the ridge of the roof. This provides complete coverage.
- Sarking is fixed by stapling, nailing or using specialised tapes. This creates a secure bond to the roof deck.
The main downside to sarking felt is the higher material cost compared to standard roofing underlay. However, the enhanced performance can make it a worthwhile investment for many homes.
Roofing felt into the gutter: Pros and Cons
Whether or not to run roofing felt into the gutter is a common debate among roofers. There are reasonable arguments on both sides of this issue.
Here are some potential benefits of extending the felt into the gutter:
- It can help minimise leaks between the roof edge and gutter during heavy rainfall.
- Felt overlapping into the gutter provides extra protection in case any tiles become cracked or damaged.
- Continuing the felt to the gutter ensures complete coverage across the whole roof.
However, there are also some downsides to consider:
- Overhanging felt in the gutter valley can cause debris build-up. This could lead to blockages.
- Excess felt in the gutter may need trimming after installation. This takes additional time.
- The practice is banned under some manufacturer warranties. Cutting felt may void any guarantees.
Overall, it’s a fine balance between potential waterproofing benefits and practical issues like blockages. Many roofers recommend stopping the felt just short of the gutter edge. This provides adequate coverage without overhanging into the gutter valley.
The decision may come down to personal preference and evaluating the specific roof situation. Proper installation is also key — with sufficient roof tile overhang and watertight joints, extending the felt may not provide significant additional protection.
Importance of Felt for Gutter Performance
Although there are pros and cons to running roofing felt into gutters, the role of felt is still important for overall gutter performance and longevity.
Here’s why proper underlay felt installation matters:
- Felt provides a vital secondary barrier even if not extended to the gutter edge. It safeguards against wind-driven rain penetrating under tiles.
- Quality felt acts as a temporary waterproof membrane during construction before the tiles are laid.
- Felt reduces the impact of rain and debris striking the roof deck. This protects the underlying structure.
- The underlay smooths out small roof deck imperfections for a neat finish.
Correct installation is crucial:
- Felt should be installed horizontally across roof rafters with an overhang into the gutter valley.
- All joints and overlaps should be securely sealed and watertight.
- Additional layers may be required for exposed sites or severe weather conditions.
While best practices differ on running felt into the gutter, proper underlay installation provides critical protection. This helps ensure gutters function effectively and drain rainwater safely from the roof long-term.
How Roofing Felt Channels Rainwater
Roofing underlay plays a key role in managing rainwater flow. The felt membranes act as a drainage layer to channel water safely into the gutters.
Here’s how it works:
- Felt is installed from the eave up the roof on a slight incline towards the gutters.
- The overlaps are arranged so water flows downwards over them.
- Felt has a textured surface that helps water run off rather than pooling.
- Joints are sealed so water cannot penetrate underneath.
When rain falls on a roof, the underlay performs several functions:
- Absorbs rainwater and channels it downwards to the gutters.
- Prevents backflow underneath tiles or into the roof structure.
- Protects against wind-driven rain entering under the tiles.
- Reduces overflow by maximizing gutter runoff.
Overall, quality felt provides an effective water management system. Correct installation is vital so the membranes can properly collect and divert rainwater into the gutters. Hence, this is key for protecting the roof and controlling moisture.
FAQ
Should roofing felt go into the guttering?
Roofing felt should overlap with the gutter by at least 50 mm. This helps prevent water ingress under the tiles and directs it safely into the gutter.
How to install roofing felt into the gutter?
Roofing felt should be laid horizontally, starting at the eaves with each course overlapping the one below by at least 100mm. The felt should be tacked in place and joints sealed with tape.
Can you extend the roofing felt into the gutter?
The roof overhang should extend 30-60 mm past the fascia board into the gutter. This allows water to drain directly into the gutter.
Does felt reduce the impact of rain?
Yes, driving rain can get through roofing felt over time. Using a double layer or reinforced felt reduces this risk.
Conclusion
In summary, roofing plays an important role in protecting a roof by providing an extra barrier against water ingress. To work effectively, roof felt should overlap with the gutter to ensure water drains away safely. However, care should be taken not to allow debris to collect where the felt enters the gutter. Overall, proper installation of roof felt and integration with the gutter system is key to long-term roof performance.
