DIY Roofing Installation Pt 1
Welcome to the detailed asphalt shingle roofing DIY Installation Guide.
Hi, my name is Richard and I will start by showing you a step by step guide to DIY roofing or home roofing for that backyard project. Here is a photo of me at Christmas lunch.
OK here we go – The diy installation of an asphalt shingle roof.
Before we start I will refer to asphalt shingles as asphalt roof tiles and asphalt tiles at times.
Measurements
Before we begin we need to take a few measurements to calculate the materials needed for the job. Generally asphalt shingles come in bundles of 21 pieces which cover 3m².
Before we begin we need to take a few measurements to calculate the materials needed for the job. Generally asphalt shingles come in bundles of 21 pieces which cover 3m².
- You will need to calculate the area of the roof to get a total area.
- You will need to measure around the fascia or the bottom of the rafters and find the total.
- You will need to measure the combined total of the hips.
Calculation number 1 will determine how many sheets of plywood you will need. A standard sheet of plywood is 2400mm x 1200mm. One of these sheets is equal to 2.88m². Generally you can work with about 10% wastage. It will also show how much asphalt impregnated roofing felt you will need – Add 10% for wastage. (more on roofing felt later). It will also give you part of your asphalt roof shingle requirements.
Calculation number 2 will show you how many metres of starter course you will need – each bundle of asphalt roof tiles has 21 lineal metres of starter course. The starter course is cut off the main shingle pieces – (I will go into detail later). This measurement will also show you how much drip edge you will need (more on drip edge later)
Calculation number 3 will tell you how many bundles of asphalt roof tiles you will need for the hips. Each bundle of asphalt roof tiles covers 8.8 lineal metres of hips (or ridge).
Calculation number 2 will show you how many metres of starter course you will need – each bundle of asphalt roof tiles has 21 lineal metres of starter course. The starter course is cut off the main shingle pieces – (I will go into detail later). This measurement will also show you how much drip edge you will need (more on drip edge later)
Calculation number 3 will tell you how many bundles of asphalt roof tiles you will need for the hips. Each bundle of asphalt roof tiles covers 8.8 lineal metres of hips (or ridge).
TIP “The plywood used is 12mm Structural A-bond (marine grade) d-face c-face tongue & groove plywood AS-NZS 2004 – 2400mm x 1200mm”
A list of tools used in this diy roofing project
Hammer, Measuring tape, chalk line, spirit level, Long straight edge, Hook blade knife, Compressor with framing gun (not necessary), circular saw set to 12mm deep cut, 15mm shank galvanised clout nails with a 10mm head, basic blade knife, 2 power cords, tin snips.
The basic frame used for our asphalt shingle roof system
This frame has been painted first. This is an excellent idea and will give a much more professional job later on.
Here we have the frame of our outdoor gazebo. At this early point you will have to run a straight edge over the rafters to check that they are all level. On this frame they were all straight.
If they are not you will need to either use a plainer to take some off the rafter or use packing strips to pack them out. We advise that there is no more than + / – 5mm every 5 metres. Due to asphalt shingles being very low profile / flat any difference in the rafter height will create a wave in the finished roof.
TIP “The rafters for this Gazebo were spaced at approx 680mm centre’s. It is much better to space the rafters at 600mm centres (centre point from rafter to rafter) so you maximise the use of the plywood and have less cutting”.
Here we have the frame of our outdoor gazebo. At this early point you will have to run a straight edge over the rafters to check that they are all level. On this frame they were all straight.
If they are not you will need to either use a plainer to take some off the rafter or use packing strips to pack them out. We advise that there is no more than + / – 5mm every 5 metres. Due to asphalt shingles being very low profile / flat any difference in the rafter height will create a wave in the finished roof.
TIP “The rafters for this Gazebo were spaced at approx 680mm centre’s. It is much better to space the rafters at 600mm centres (centre point from rafter to rafter) so you maximise the use of the plywood and have less cutting”.
Here you can see I started by setting up a basic plank on two ladders
Here I have set up a basic plank between two ladders which is usually more than adequate for a job like this.
This spirit level has a special tool that measures pitch
Roof Pitch
At the bottom of this spirit level there is a special tool to measure the pitch of the roof. This roof was 25 ° pitch. The minimum pitch for an standard asphalt shingle roof installations 18.5 ° pitch. Between 18.5 ° pitch and 9.5 ° pitch you will need to use a special waterproofing barrier eg.. IKO winterguard – which is an adhesive backed rubberised roll available from www.roofing-materials.com.au It is also acceptable to use a double layer of asphalt saturated felt material. Asphalt shingles can be installed all the way up to a vertical wall, however between 60 ° pitch and vertical (steep slope roof) you will need to self seal each tab of the 3-tab asphalt shingle.
TIP “Both on steep slope roofs and on roofs subject to high winds you may need to use asphalt roofing tar under each tab of the asphalt roof shingles for proper adhesion. Place a small dab of roofing tar under the middle of each tab the size of a ten cent piece. This will prevent blow off.”
Checking that the bottom of the plywood is flush with the bottom edge of the fascia
I am checking the position of the plywood so that it comes to the outside edge of the Fascia board. Note I am spanning the plywood the long side horizontally which is normal application. If you have a roof where the plywood fits better running vertically then this is fine. Always try to stagger the sheets of plywood for extra strength – this also complies with the manufacturers guidelines.
TIP “Butt the tongue and groove ends of the plywood tight together but on the short sides leave a 2 – 3mm gap to allow for any expansion the plywood may have.”
Nailing the first sheet of roofing plywood into place
Once you have the first sheet of plywood in place you can hammer in a couple of nails to hold. Don’t hammer the nails where you are likely to cut the ply eg.. on the end rafter or down the hip. Make sure you have brought the plywood slightly past the corner edge so it will line up on the other side. Note the tongue in the plywood is on the top side.
TIP “Plywood will generally have a stamp on one side with ‘A-Bond AS/NZS 2004….’ it is a good idea to lay all of the roofing plywood with the stamp on the top side (or bottom side) as this will make fitting the tongue into the groove much easier”.
Chalkline for cutting up the centre of the rafter
Here I am snapping a chalk line on the centre of the rafter for a clean straight cut. At this point measure the blade on your circular saw to cut exactly to the depth of the plywood to avoid any mistakes. Due to the shape of this roof and the wide spacing between the rafters there will be quite a bit of wastage in plywood. “Always think 600mm centres on the rafters”
TIP “Be sure to use the water soluble chalk as the other semi permanent chalk will stay on the asphalt shingles”.
Carefully cutting straight up the plywood
Simply cut straight up the chalk line. Some of the waterproofing chemicals in plywood are known to cause cancer so be sure to use a basic mask. Here I’m holding my breath – I Think!!
Taking measurements up the hip
Here I am simply marking more lines and filling up the spaces with plywood. Take your time here to avoid easy mistakes.
The deck becomes extremely slippery so its a good idea to sweep
Sawdust and plywood are very slippery so sweep as much as you can. As you can see you are creating a fantastic deck that you can walk on as much as you like. No denting metal or cracking tiles.
OK. Bored yet! Now using standard framing nails (50mm long shank) nail the plywood down every 150mm on the edges of the plywood and 300mm in the centre. Now measure and mark each nail spot – just kidding “it’s getting late” Be sure to hold the nail gun vertical or your nails will shoot through on an angle underneath. I’ve done this heaps of times and I shot quite a few through on the wrong angle (these rafters were very thin!!). If this happens you will have to knock them back up from underneath.
TIP “For a roof that is designated in a high wind zone, is over 8 metres off the ground or you know just gets bloody windy nail the entire sheet every 150mm. This is called storm nailing and will conform to most plywood manufacturers guidlines”.
Always leave a 2-3mm gap in the plywood on the short end
Here we are just repeating the process on each side of the gazebo. It is always a good idea to stagger the pieces of plywood running up the roof. This will increase the structural integrity of the roof. On a small gazebo like this it is not that important and you will find yourself using most of the leftover pieces.
TIP “Allow for a 2-3mm gap on the short length of the plywood. This gives room for the plywood to expand as it takes on the moisture of the surrounding environment. You should but the tongue and groove ends together with no gap. There is a machine cut gap on this long edge.”
The cladding on the roof is starting to take shape
Be sure to keep your tools and cords fairly tidy.
This side of the gazebo has a 3.5 metre fall from the fascia.
Anything over 2 metres in height is considered a high fall and certain measures should be taken. This is a 600mm wide aluminium scaffold that is very lightweight and portable – perfect for this job. You can see the scaffold is secured onto the fence for added support.
TIP “A lightweight alluminium scaffold is very easy to put together and is not too expensive to hire.”
My head height is approx. 4 metres high. A Fall Could Cause Serious Injury
It is always a good idea to clear the area below – like that tennis court roller.
There are small gaps where the plywood meets the wooden ball - these will be fixed later.
This looks a little messy where the plywood meets at the top, however there is an easy fix that I will show you later on. If you look closely at the joins you will notice that the nails are all 150mm apart and staggered.
Use some tin snips to cut the corners of the drip edge material
This drip edge is 110mm with a 90° bend then 25mm with a 10mm upturn. The colour is on the outside – in this case Woodland Grey to match the gazebo. The purpose of this material is to protect the bottom edge of the plywood from the water running off the roof.
It serves more of a purpose when installed with gutters as it protects the plywood from the back splash of the water. Another option when building a structure without a gutter is to paint the end of the plywood protecting it from any water.
Nail the drip edge to the lower edge of the plywood
Hammer a nail half way in on both ends of the face of roof 100mm up from the bottom edge of the plywood and snap a chalk line. This will be used to position the drip edge 10mm below the bottom edge of the plywood. Overlap the drip edge material 100mm at the joins.
TIP “Instead of cutting the drip edge material diagonally up the hip it is a good idea to carefully bend the material over the hip and nail in place.”
Asphalt saturated felt paper used to cover the entire roof area
This is a full roll of asphalt Saturated felt material that is used to cover the entire roof area. There are a few reasons we use this material instead of installing the asphalt shingles directly to plywood. The use of the roof felt paper gives the entire roof system a Class A fire rating – Resisting severe exposure to fire. More details atwww.roofing-materials.com.au. The roofing felt paper also protects the asphalt roof shingles from toxins leaching out of the plywood. Roofing felt paper provides added protection against severe wind driven rain and reduces the instance of picture framing which is the visible outlines seen when the plywood is not perfectly flat.
Lay the asphalt saturated felt material accross the roof starting at the bottom. The bottom edge of the felt paper should be in line with the bottom edge of the drip edge. When joining you should overlap 100mm on the vertical joins and overlap 50mm on the horizontal joins. The easiest way to fasten is with a hammer stapler but a heavy duty stapler will do just fine. The staples are only there to hold the felt paper in place. When it is windy it is useful to have someone to help as it is hard to keep the paper in place.
TIP “Be aware that the asphalt saturated felt paper is only stapled down and it can slip under your feet. This becomes more of an issue the steeper the pitch is.”
Starting to roll out the asphalt saturated felt material in line with the drip edge
Roll out the asphalt saturated felt material starting in the corner of the roof plane. Line up the bottom of the felt material with the bottom edge of the drip edge or the bottom of the plywood – whichever you have. A good guide is to staple 3- 4 staples vertically and about 50mm apart horizontally. Be sure to keep the felt material tight as you roll it across the roof. When you reach the other edge simply cut the felt material with a stanley knife.
Staple down the felt material with a hammer stapler
Click here to go to DIY roofing installation Part 2