How Many Nails Needed For Roofing Felt?

After deciding to use roofing felt as your underlayment, the next thing to worry about is how many nails for roofing felt you need. Roofing felt is a fibreglass fleece infused in asphalt to provide waterproofing. It helps protect the roof from damages by elements.

Roofing felt consists of natural materials, and besides being water-resistant, it can also withstand more sun and wind than some types of underlayment. Roofing felt is mainly used by homeowners with flat roofs, and it can also be a good fit for sloping roofs. Ask a professional if you need to learn more about commercial roofing service.

What Are the Types of Roofing Felts?

Choosing the best underlayment can be challenging. After a bit of research about roofing felts, you’ll remain with one more challenge: selecting the felt type. You can also consut with the specialists doing roofing in aurora.

There are three types, and all have unique features. Before selecting any, it is advisable to look at the characteristics of each kind to confirm if they meet your desired needs.

The option you choose should also fall within your budget. If you don’t have enough funds to finance the roofing project, you can opt for roof financing in Lubbock.

Here are the different types of roofing felt underlayments.

Torch-On Felt

To make a torch-on felt, three layers of bitumen are melt-welded onto a roof, and a waterproof seal gets created using a blowtorch. A vapour control sheet reinforced felt and a cap sheet with a mineral finish are the three layers of bitumen used.

Building regulations require that all habitable houses should use a torch-on felt made using the three layers. Other rooms like the shed can get roofed with a two-layered one.

One of the advantages of this felt is that it is easy to install, and you can quickly install it in wet and dry areas without complications.

It also has a high resistance to wind, rain, and intense UV rays. The felt is also energy efficient since it does not allow heat transfer from outside to inside.

However, it is impossible to DIY this roofing underlayment because of the welding, which an expert can only do. You can learn more here about the bitumen roof.

Self-Adhesive Felt

Unlike torch-on felt, which only professionals can install, you can DIY the self-adhesive felt. Its installation is easy because you only need to peel the release film and stick it on the surface. It is also waterproof and provides a perfect moisture barrier, so you don’t need extra adhesive tapes.

Self-adhesive felt is flexible during installation, and you can easily install it around ridges and hips. The underlayment is lightweight, making it easy to install, and installers can easily maneuver through it. This roofing felt best suits roofing for garages and shades. If later years you find some gap in roofing, you can call specialists for Felt repairs.


For the shed-felt, you can choose either one with the torch-on or self-adhesive type of applications. This roof felt suits roofs of sheds and garden buildings. It is coloured, and this improves the building’s curb appeal.

Facts About Roofing Felt Installation

After choosing the type of felt to lay on your roof, the next big task is installing the underlayment. If you want to DIY, you must first collect all the tools needed and make sure you have them near you, to make work easier and fast.

If you are doing a reinstallation, you should remove the old roofing felt first and clean the area. You should never leave any nails or debris after the installation.

Ensure you are installing the felt on a clean timber that is in good condition. Check for any rots and damages. Check for water damage around the area where there were old nails. It would help if you also replaced old and rotting timbers.

You can also apply a wood preserver to give them a longer life. If you do so, ensure the preserver dries first before you proceed.

Always measure the roof you are installing the roofing felt on first. This will help you know the size of pieces you will cut for each side when installing the roofing felt.

Always start with the bottom towards the top of the roof. Read the manufacturer’s instructions to know the best way to apply the underlays. Installing the felts from bottom to top on slopping roofs ensures that the rainwater will not run under the overlaps.

When you are laying the felt from bottom to top, ensure you nail down all the parts you have installed before stepping on them. Hold the felt with two hands when laying it on the roof, pull, straighten and then align it to ensure it is straight.

How Many Nails Needed For Roofing Felt?

When installing the roofing felt on your roof, you should use nails with uniform rolls. Every part already laid on the top should be nailed down first before you start walking on it.

You must also be careful to ensure no wrinkles and folds on the felt before you nail it down. The nails should be spaced 6 to 8 inches apart, so the total number of nails you will use will depend on the size of the roof.

Avoid using cement on the roofing felt, especially if you plan to re-shingle the roof that day. That is because the cement will take longer to dry, and when you remove it after it dries, you will cause damage to the roof.

Does The Roofing Felt Have Disadvantages?

After the felt starts wearing out, it becomes less effective. You will need to repair it to ensure it serves its purpose well, reducing its curb appeal. If you do not want to tamper with your roofing felt’s aesthetic, you only have one choice; replacing the entire felt.

The roofing felt does not have a very long life span. After 10 to 20 years, you will notice that it is wearing out, and you’ll need to start thinking of a replacement. Harsh weather also accelerates its wear and tear. Besides that, it is durable and requires minimal maintenance.

Roofing Felt Maintenance Tips

Felt roofs are helpful on various buildings, from garden sheds to schools, hospitals, and homes. Felt is a great material for flat roofs and is very durable, but proper care is important if you want it to last. Maintaining the good quality of your felt roof will help extend its life and protect your property from potential leaks. Felt roof maintenance is recommended, and spot repairs are easy to do. Also, if you are unsure or have concerns, always seek professional help. Here are some things to remember to keep your roofing felt at its best. 

1. Keep it clean

Since a felt roof is flat, it can easily collect dirt and debris over time, especially when weather conditions are harsh. Keep the felt roof clean and free of leaves, branches, and debris. If the thatch is near the ground (such as above a shed), use a broom to remove debris. Always ensure your felt roof is safe to walk on or hire a professional company before cleaning. Cut down nearby trees if branches are sticking out or touching the thatched top. Branches can scratch and damage roofing material. It also makes it easier for moss to build up on your roof, which can trap moisture and cause damage.

2. Check surfaces and detailing

Ensure that the overlap between roofing materials is tightly sealed, that the mortar or sealant is free of damage, cracks, or tears, and that the uprights are securely fastened to the wall. Be careful of air bubbles on the felt material’s surface. Bubble size should be checked regularly, and any swelling should be reported to the roofer. 

3. Check for leaks regularly

Cracks in felt roofs can cause water leaks, and it’s important to repair the damage immediately. A leaky roof can have devastating effects on the interior of your building, so check your roof regularly for signs of leaks or damage. Flat roofs will likely leak around the edges and at seams, so inspect these areas carefully. Cracks or tears along the roof deck joist line can be caused by heat or moisture transfer, oversaturation of the insulation, or sagging of the roof deck. This can be repaired by cutting back the existing felt, allowing the area to dry, then properly overlapping the new and existing material and applying a new layer of heavy-duty felt.

4. Add coating

Liquid coatings provide seamless roof coatings that can be applied to felt materials. Coatings are an excellent choice when previous repair or refurbishment methods have failed, adding a highly durable and waterproof layer to protect your felt roof from damage. Although not something found in felt roofs, internal condensation can result from poor insulation. It can also be an indication of inadequate ventilation. Internal condensation can lead to the rotting of wooden supports and eventual structural collapse. Always consult a roofer if you suspect internal condensation in your building. 

Final Words

Identifying the underlayment system to install on your roof is challenging, but choosing the type of roofing felt is even more challenging. Knowing how many nails for roofing felt you’ll need for the entire process will depend on the size of your roof.

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