Ontario's Premier Fabricator and Installer of Metal Roofing
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Frequently Asked Questions


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When it rains is a metal roof noisy inside my home?
NO. Contrary to popular beliefs, metal roofing is very often quieter than an asphalt shingle roof. This is due to the fact that metal roofs float over the roofing deck creating an air space between the metal roof and the roofing deck. This extra space creates a sound barrier, so to speak. The underlay coating used by London Eco-Metal Manufacturing Inc. provides additional noise reduction properties.
How long will a metal roof last?
A properly installed metal roof will last you a lifetime. Superior technology finishes provide long-term protection against peeling, blistering, cracking, splitting and delaminating. There is an option of restoring and recoating the finish in 40 or 50 years time in order to extend the longevity of your metal roof.
How much do metal roofs cost compared to asphalt?
The upfront cost of metal roof is higher than that of an asphalt shingle roof. However, a metal roof is a long-term investment as it will outlast several asphalt roofs. That is why metal roofs will always cost less in the long run since the homeowner will save the additional cost of replacing several asphalt roofs. London Eco-Metal Manufacturing Inc. manufactures and installs its products. Solid sheeting roofs are the most affordable roofs on the market in comparison to other metal roof products.
Are there standard ventilation requirements?
Proper ventilation is one of, if not the most important key factors in the life expectancy of a roof. Depending on the type of roof and its slope, asphalt roof requirements can range from 1sq. ft. of ventilation for every 300 sq. ft. up to 1 sq. ft of ventilation for every 150 sq. ft. For example:
1000 sq ft roof require 3 to 7 vents
1500 sq ft roof require 5 to 10 vents
2000 sq ft roof require 7 to 14 vents

Metal roofing systems installed by LEMM use ridge venting as a standard, which is the most effective venting system for your home.
Does London Eco-Metal Manufacturing Inc. have a product warranty?
Yes. We offer a transferable 55 year warranty.

We are one of only three companies that have a warranty with the paint manufacturer - Beckers.

Beckers provide London Eco-Metal Manufacturer the BeckryTech material produced by ArcelorMittal in Canada under the trade mark Granite Deep Mat.

Steel materials have an automatic guarantee provided by the manufacturer. (G90 or 275 g/m2). The guarantee applies automatically from the moment the product is delivered to the client, so there is no paper guarantee issued to the client.

The Automatic guarantee is not conditional upon mandatory annual maintenance inspections.

For roofing applications, the slope of the roof has to be a minimum of 3/12 and the guarantee is not dependent on roof orientation.

Freedom of part design is covered by the guarantee.

Property ASTM Method   Granite Deep Mat
Film Thickness D5796, D1005, D4138 Mil 1.0 +/- 0.2
Formability/Adhesion (T-Bend test) D4145   2T no taped removal
Gloss (60 degree) D523 GU <6
Film integrity     40 years
Colour Change D2244 Vert. 30 years – dE 5 max
    Non-Vert. 30 years – dE 8 max
Chalking D4214 (Method A) Vert. 30 years – 8 min
    Non-Vert. 30 years – 6 min
Geographical Limits     Canada and Continental U.S.
Application Guide     Granite Deep Mat
General market application   Product
Residential and commercial
buildings, roof panels (tile profiles)
Climates, country, regional localisation   Weathering
Typical UV and temperature
conditions in North America.
Environments, air pollution, chemicals resistance   Corrosion
Normal environments (rural, urban and light industrial)
My building is naturally washed by rain. Do I need to do additional maintenance to benefit from the automatic guarantee?
No. No additional maintenance is required in order to benefit from the automatic guarantee.
Do I need to do something to be covered by the automatic guarantee?
No. The guarantee automatically comes into effect from the moment the product is shipped. Registration is not required.
Will the colour fade over time?
Our metal roofs are painted with high performance polyester to a thickness of 35 µm Granite Deep Mat Wrinkled coating applied to a galvanized steel substrate with a zinc coating with a minimum 275 g/m² for Granite that has exceptional weathering properties. Over time, a slight change in color might be noticed as the settling of airborne contamination occurs. The rain or washing the roof with a garden hose will help to keep the roof looking like new.
Will my metal roof rust out?
Today, in order to provide our customers with a trouble-free roof, metal roofing material goes through the process of several baths. The different manufacturers have slightly different approaches. Rust on steel is eliminated with a zinc/aluminum coating or with several coatings of various kinds. However, if untreated metal is used, some rusting will occur.
Is a metal roof safe in a storm or when it is lightning.
The likelihood of lightning striking your home will not increase because your house is covered by a metal roof. In fact, if your home were hit by lightning, your metal roof would disperse the energy safely throughout the structure. Metal roofing is not flammable or combustible. Metal roofing is considered to be a desirable, low risk roofing option for areas with severe weather conditions including lightning.

It is believed that the metal roof may act like a Faraday Cage, allowing the lightning to travel around its surface and go to earth by the path of least resistance. That is exactly why a person is safe in a car during a thunderstorm. The metal acts as a good conductor and directs the current around it, discharging to the ground. The tires are actually more conductive than they are insulating.
Is a metal roof damaged by hail?
Metal roofs are highly resistant to hail damage. In fact, metal roofs are much more hail resistant than asphalt/fiberglass shingles. Many metal roof products have the highest impact resistance and hail rating granted by the insurance commissions in the hail belt regions in the U.S. Some insurance companies might offer reduced rates for houses with metal roofs.
Can I walk on the roof?
You can safely walk on any metal roof without damaging it. Before you walk on your roof however, we recommend you talk to your installer or us first. Based on the style and the pitch of the roof, the appropriate details on how to walk on a particular roof will be provided by our experts.
Is a metal roof environmentally responsible?
Not only is metal roofing great for your home, it is ideal for the environment. The recycled content of the steel in a metal roof is about 56% from production, to installation, to reuse, far surpassing asphalt. National Association of Homebuilders Research Center reports that each year, 20 billion pounds of asphalt shingles are dumped into U.S. landfills. Metal roofing helps to reduce excessive shingle waste as it can often be installed over the current asphalt shingle roof.

Metal Roofing Terminology

Terminology used to describe roof types and components might be a foreign language for those who are not familiar with it. While it is appreciated that certain words have other meanings we have listed below an explanation of words used when discussing the structure or type of roof.

Roof Types:

Cross Gable: to a gable roof (see below), but has two gable parts that cross in a “T” like fashion.

Cross Hipped: Similar to a hipped roof (see below) but this type has two parts that cross.

Flat: A flat roof has no slope at all.

Gable (see cross gable above): A simple triangular shaped roof from the side with two rectangle sections opposing each other creating an upside down “V”.

Gambrel: This roof looks more traditionally barn or bell shaped than triangular when viewed from the side. It is like a flattened gable roof. Many farms have gambrel roofs.


Hipped (see cross hipped above): A pyramid shaped roof where four triangle sections are sloped to meet in a single point.

Pavilion Hipped: A simple triangular shaped roof from the side with two opposing isosceles trapezoids that meet at the hip of the roof thus creating two angled sloped triangles sections. This roof type is typically a low-pitched roof.

Mansard: This roof type has a lower sloped area at the top with four heavily sloped sides slanting out to meet and/or exceed the walls of the building.

Shed: A single sloped roof.

Saltbox: Similar to a gable roof, but the two sides are not symmetrical.

Other Important Terminology

Metal Roofing: Unfortunately, in the past, metal roofs were not designed with esthetics in mind. Let’s be honest, we have all seen those old, boring and unimpressive tin roofs on farm buildings. But in fact, these roofs were very durable. Farmers put them on their farm buildings strictly for practicality as metal roofs are designed to be a long-term and no-maintenance solution. Many historic and artistic buildings were capped with aluminum over 100 years ago.

No longer an ugly duckling, metal roofing comes in a rainbow of different colours, a multitude of exotic finishes and elegant profiles. Our superior quality coatings provide energy efficient solutions for today’s homeowners. Additional benefits of metal roofing not offered by asphalt shingles include, but are not limited to absence of mold, mildew, cracking, rotting, chipping, and curling. Its fire resistant properties and the ability of snow to slide off of the roof, represent additional safety characteristics of the metal roof.

Metal pricing goes from steel on the low-end to aluminum (mid) and to copper (high end). Aluminum is considered to be the “miracle” metal. It is extremely light and for years it has been used to build airplanes. Worldwide demand for aluminum has caused its price to rise in recent years. Nevertheless, it is an ideal building material in many industries. Like steel, it is available in a variety of colours and profiles. Before you dismiss metal roofing as too expensive, contact London Eco-Metal Manufacturing Inc. for a quote, because metal roofing represents your best step up the performance ladder.

Beam: A long piece of wood or steel supporting your roof and when grouped, can form a truss.

Coverage: The degree of weather protection offered by a roofing material: single, double or triple coverage.

Decking/Sheathing: Normally plywood which provides a flat surface covering your home.

Dormer: A gabled extension protruding from a sloping roof, usually to allow for a framed window.

Drainage: Shape, layout and slope of roof for the purpose of shedding water, ice, and snow.

Drip Edge: Weather-resistant metal or vinyl edge installed along eaves and rakes to facilitate shedding of water at the edges.

Eaves: Parts of a roof that project beyond or overhang the face of the wall.

Eavestrough: Also known as gutters. They provide a method by which water dripping off the roof is caught and carried to the downspouts and then carried away to an appropriate area.

Exposure: Specifically, exposure to weather. Also the distance from the butt edge of one shingle to another.

Fascia: The vertical edge of the roof, either behind the eavestrough or at the edge of a gable.

Felt: A breathable type of building paper made of a strong, tough base saturated with asphalt.

Flashing: Material used to prevent leaking/seepage at certain vulnerable spots like valleys, top or end-walls and chimneys.

Gable: The end wall of a building which comes to a triangular point (upside down “V”) under a sloping roof; also a type of roof.

Hip: An external angle formed by the meeting of two sloping ends of a roof, from the ridge to the eaves; also a type of roof.

Rafters/Trusses: A framework of beams, usually grouped in a triangular nature supporting the roof.

Rake: The inclined edge of a pitched roof.

Ridge: The apex of the angle formed by a roof, or the peak, where the common rafters meet.

Roof Covering: Most common are asphalt shingles, wood shakes, metal, clay tile, slate or copper.

Sofit: The horizontal bottom of the roof overhang.

Square: The amount of roofing material required to cover 100 square feet (10'x10') of roof surface.

Underlayment: A layer of moisture protective material between the decking and exterior roof covering. In northern climates an ice and water shield helps to minimize ice damage problems.

Valley: An internal angle or water runway formed by the intersection of two slopes on a roof.

Venting: Proper venting is necessary for maintaining air-flow and overall roof “health.”


531 Shaw Road
Dorchester, Ontario, Canada
N0L 1G4

Phone: 519-451-7663
Fax: 519-451-7669
Toll free: 1-855-838-9393

head office and manufacturing facility Dorchester (London)


960 Ch. Burton Road
Vars, Ontario, Canada
K0A 3H0

Phone: 613-443-9393
Fax: 613-443-9399
Toll free: 1-844-778-9393

manufacturing facility Vars (Ottawa)


531 Shaw Road
Dorchester, Ontario, Canada
N0L 1G4

Phone: 519-659-3224

showroom Dorchester / London
1759 Britannia Rd. E. Unit #6/7
Mississauga, Ontario, Canada
L4W 4E1

Phone: 905-564-7663
Toll free: 1-833-377-9393

showroom Toronto (Mississauga)
960 Ch. Burton Road
Vars, Ontario, Canada
K0A 3H0

Phone: 1-613-443-9393
Toll free: 1-844-778-9393

showroom Vars (Ottawa)

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