Warm Roof vs Cold Roof:

What is a cold roof?

A cold roof is where the insulation is at ceiling level and there will be a void above the insulation and underneath the waterproofing layer (Think traditional roof space or attic) 

This type of insulation will usually be loft wool type insulation and can have gaps if it is moved or has not been fitted properly.

Because of these gaps and the wool type insulation not being totally solid, warm air can pass through more easily and meet cold air dropping in from above.

This causes condensation and vapor to form.

Cold Roofs need to be ventilated because of this.

The air between the top of the insulation and the back of the roof covering is “cold” hence the term “Cold-roof”

What is a warm roof?

A warm roof is a roof that is insulated above the rafter or joist in one continuous sheet instead of being cut and fitted between the rafter or flat roof joist.

The waterproofing layer of the roof is directly fitted over the insulation slab with no air between.

This method of insulation is more efficient as there are no gaps or inconsistencies in the insulation.

A warm roof is comprised of a solid insulation board which is a similar material to polystyrene.

Warm Roofs do not usually require any ventilation as the continuous solid slab of insulation does not allow the warm and the cold air to meet and condensation cannot form because of this.

The air under the insulation slab is kept warm hence the term “Warm-roof”

Types of insulation:

A warm roof is a roof that is insulated above the rafter or joist in one continuous sheet instead of being cut and fitted between the rafter or flat roof joist.

The waterproofing layer of the roof is directly fitted over the insulation slab with no air between.

This method of insulation is more efficient as there are no gaps or inconsistencies in the insulation.

A warm roof is comprised of a solid insulation board which is a similar material to polystyrene.

Warm Roofs do not usually require any ventilation as the continuous solid slab of insulation does not allow the warm and the cold air to meet and condensation cannot form because of this.

The air under the insulation slab is kept warm hence the term “Warm-roof”

PIR Insulation.

This is a solid polyurethane board usually laminated with a silver foil on both sides. (Kingspan and Celotex are the most well known brands)

To meet normal building regulations in the UK, a slab of 120mm thick will be required.

The PIR boards can be cut and fitted between joists(Cold Roof), or fitted over the joists in one continuos slab, (Warm Roof).

This insulation type is more expensive and takes longer to fit than wool insulation.

If fitted in a warm roof scenario, no ventilation is required.

Kingspan-TP10TF70TW55-Insulation-

Loft Wool Insulation

Many years ago this would have been made from fibreglass but is now usually a recycled plastic that resembles the old fibreglass type material.

To meet normal building regulations in the UK, a total thickness of 280mm thick will be required.

This is normally laid in a traditional attic or loft space on top of the plasterboard ceiling.

Loft wool is a very efficient method of insulating a cold roof space if fitted correctly with the right ventilation.

It is important not to block off any ventilation paths with this type of insulation. These ventilation paths will normally start at eaves level behind the guttering and allows air to crossflow and circulate within the roofspace, and take away any vapours that might build up.

knauf-loft-insulation-loft-roll-44-combi-cut-1005-p.jpg_2_3

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Stace Roofing Ltd
5.0
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Richard Hind
Richard Hind
06:48 25 Jul 21
An excellent job by a skilled team. Now looks fantastic.
Michael Toone
Michael Toone
10:57 11 Apr 21
I have used Stace Roofing on two separate occasions. They are an excellent user-friendly family business who offer a... variety of roofing solutions. In 2017 the roof of a large bedroom dormer window was leaking. Stace recommended a complete flat roof replacement including 6" of insulation to bring the roof up to modern building regs. Last week the same team replaced the flat roof over the kitchen extension using a different solution. Stace will recommend the solution that suits your circumstances at the time. A friendly and efficient, independent scaffolding service is included in your free quotation. I have no hesitation in recommending the Stace family business for all your roofing requirements. They do what they say they are going to do.read more
Ray Wilson
Ray Wilson
08:46 01 Feb 21
Water ingress into the back of the house from the roof & rear chimney. The guys arrived on time and completed in good... time despite the bad weather. They knew what they were doing and got on with it. Happy to recommend them for your repairs and to use them again myself.read more
Abdul Mannan
Abdul Mannan
07:54 18 Jan 21
The Stace Roofing team were very professional and attentive. Every aspect of the work from initial site visit to... completion of work was carried out professionally. Thanks.read more
Robert Stubbs
Robert Stubbs
12:01 22 Oct 20
My existing flat roof extension was nearing its life expectancy and I decided to replace the old felt with rubber and... at the same time upgrade it from a cold roof to a warm roof. I chose Stace Roofing as they were used to doing rubber installations. They were not the cheapest but to my mind offered a professional service. I was very happy with how the job was handled and the finished product, so can happily recommend them.read more
Sue Jones
Sue Jones
09:49 18 Sep 20
It was only a small job, a kitchen extention roof re felting, but I was treated exceptionally well by all the staff,... both in the office and the man who did the actual work.He was friendly, courteous and worked hard, while still observing the Covid 19 rules. The work he did was really neat, tidy and was done in the time specified and the whole area was left really clean. The roof looks very smart!I highly recommend Stace Roofing for their professionalism and high standard of work.read more
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What Our customers are saying

It was a pleasure dealing with a Company that provides a highly professional and considerate service. I have received a number of (good) comments regarding the works from neighbours and also a note through the front door - all of whom asked who was carrying the work and for your contact details which I have passed on - I hope you get at least one enquiry from those.

Simon Barnes

Stace Roofing provide a quality professional service delivered by skilled staff who are polite, considerate and leave the site clean and tidy.

Mr P Roffey

Stace Roofing have consistently supported our works with excellent workmanship, friendly advice, great flexibility and assistance above and beyond the call of duty, providing a user friendly non-contractual service, favouring open and honest discussion.

Mr Martin Kempler

How refreshing to deal with a thoroughly professional company who understand customer service and quality work. The team treated my house as a home not a building site and nothing was too much trouble. I would have no hesitation in recommending them

Simon King

Your Responsibilities for the Conservation of Fuel & Power

Since October 2006, Under the government’s new part L regulations, you/we have to notify your Local Area Building Control officer (LABC) when over 50% of a flat or pitched roof is being replaced.

They will insist that they are called in to inspect the roof and make sure your contractor has fitted the correct amount of insulation in place. LABC will make a charge for this.

Normally it would be an estimated cost of around £240.

If you don’t comply with this, then you risk a fine of up to £5,000, plus the cost of putting the work right if it isn’t up to the required standards.

The other risk when avoiding this ruling is that if you ever sell your property, you will not be in possession of a building works completion certificate (Part L Compliance) for your new roof and insulation.

This document is asked for by every solicitor dealing with property conveyance and can cause major headaches in the middle of an already stressful house sale.

Luckily for you, we are certified to carry out that inspection for you without the need of a Building Control Officer.

Stace Roofing are licensed under the NFRC 'Competent Person' scheme (NFRC-CPS), which allows us to certify any qualifying roofing and insulation work to your property.

We provide you with this service absolutely free saving you £240 in additional LABC fees.

On top of this we also provide an insurance-backed 10-year guarantee, covered by 'QANW' to cover you in the event that you ever have any future problems.

You’ll be issued with a Buildings Regulations Compliance Certificate directly from the CPS department office.

So, in a nutshell, the law states that you have to insulate and ventilate any part of your roof if over 50% of it is being stripped.

Please ensure your contractor is either using the Competent Roofer scheme or your LABC.

Click Here for an example of your 10 Year Insurance Backed Warranty and Part L Compliance Letter required with all insulated roofs.