How is Re-roofing Different from Roof Replacement?

11th July 2023

Keeping your roof in good condition is essential for protecting your home and keeping everything inside of it safe. As a homeowner, it is important that you do regular assessments and checks to see if your roof has recently undergone any damage or wear and tear. If you spot anything out of order, such as missing shingles or water damage, it is probably time for re-roofing or a roof replacement.

Unsure which method to go for? Read on to find out more about re-roofing, roof replacement, how they differ, and which option might be better for your own roof.

What is re-roofing?

Re-roofing involves layering new shingles or roofing material over the existing shingles or roof surface. It is an alternative to entirely replacing or removing a roof, and is one of the quickest and most affordable ways to restore your roof’s appearance, given it does not involve labour-intensive processes or many new materials. This process can be done if your roof is still in relatively good condition and not showing any major signs of damage. However, re-roofing can only be done a certain number of times, usually up until you add a third layer of shingles, as there could be existing damage underneath all the layers that cannot be seen.

What is roof replacement?

Roof replacements require the full removal of the existing structure. The old shingles or surfaces are stripped off to expose the damaged roof deck so it can be repaired. This requires a lot more time and effort than re-roofing, but results in a strong roof structure that addresses the underlying issues. Complete roof replacement should only be done when your roof is severely damaged or heading that way.

How are re-roofing and roof replacement different?

There are a few key differences between re-roofing and roof replacement, including:

Time and effort

As re-roofing only involves installing new shingles or a new material layer over the existing surface, it is the fastest and less labourious way to restore your roof. On the other hand, roof replacement requires stripping off the entire roof to replace with a completely new roofing system, hence it needs much more time and effort.


Re-roofing is generally more cost-effective than roof replacements, as this method requires less work and materials. Roof replacement can be quite costly due to the intensive time, labour, and materials required.


If your roof only has some minor damage, such as missing or worn shingles, small leaks, or surface cracks, then re-roofing is a good option to repair wear and tear at a minimal cost. Severely damaged roofs that show signs of water damage, mould, broken shingles, or dents should get a full roof replacement, as these issues can hardly be solved by a quick fix.

How do I decide which method is best for my roof?

Now that you are aware of the key differences between re-roofing and roof replacement, you can assess your roof to see if it has mainly smaller damage or if it looks like it is going to reach the end of its lifespan soon. This is the most common way to judge whether your roof just needs some re-roofing or a full roof replacement.

Explore waterproof roofing solutions with ARDEX

If you fall into the re-roofing category, ARDEX has several waterproof coating solutions that could help protect your construction projects from the elements. Our liquid applied roof coating, epoxy waterproofing, and liquid applied roofing systems are highly effective waterproofing products that help strengthen and repair existing roofs. We also provide solutions for carpark coating in Hong Kong. If you are in doubt and want some professional advice, contact our team, and we can walk you through our high-performance speciality building materials to help you find the best waterproofing solutions for any construction project.


How do I know if my existing roof needs re-roofing or replacing?

You can check your roof for any major or minor damages to determine whether it needs re-roofing or replacing. In general, minor damage will range from leaks, a few missing shingles, some cracks, or general wear and tear. Major damage should stand out to you when you do your roof inspection, including mould growth, termites, water damage, or noticeable deterioration.

When is re-roofing a better option than roof replacement?

Re-roofing is generally better for roofs that have superficial damage or wear and tear.

What are the benefits of re-roofing?

Re-roofing offers several benefits, such as reducing maintenance costs, extending your roof’s longevity, providing additional safety and insulation, and creating a fresh look for your roof.

How long does re-roofing take?

Generally speaking, re-roofing can take a couple of days up to a few weeks to complete depending on the amount of damage and the individual roof’s requirements. It will most likely be completed faster than a full roof placement.