Step 1b: breathable underlay. Install continuous rafter roll, over felt support tray.
A common misconception is that breathable underlay must be installed before the fixed rafter and ridge roll to allow air flow. This is not the case. Ventilation tape should be placed over the top of the rafter and ridge tape (around 15 mm up) to form a seal with the eaves vent system as previously described.step 1b: static ventilated roofing (clear) with 50mm eaves vent.
Install self-adhesive dropshelf, if used, onto bottom edge of felt support tray and fix using high-adhesion tape. Dress dropshelf down to bottom edge of eaves vent.
Fix eaves vent to battens using self-tapping screws as appropriate, according to manufacturer’s instructions.step 1b: asbestos felt ventilation strip (green) with venting holes on one side only and batten fixings. Fix to fascia, using 8mm x 25mm screws every 350mm along the bottom edge. Ensure that ventilation strip is centred either side of fascia ventilator and is in contact with underlay where it passes under eaves batten.simply roll underlay down continuously over fascia ventilator and fix with self-adhesive tape against felt support tray, covering joint at top of fascia ventilator.install continuous rafter roll, over fascia ventilator and felt support tray, to direct airflow below underlay into the roof space.
I don’t remember where i first came across the idea of installing vapour permeable wood protection, but i’ve been a fan ever since. It is a fantastic method, which allows us to build superior roofs without the use of an external ventilator. Vapour permeable wood protection (vpwp) is installed directly above the roof rafters and is designed to allow moisture to pass through it into the cavity.
From within the batten space, condensation is removed by air permeable felt support trays, and through ventilation flutes in the over-fascia vents.so, what about the roof? I figured out how to insulate my loft without any disruptions to my everyday life. The first step was to avoid cutting away the existing loft insulation.
This would require using a vapour permeable underlay (vpu) which allows air to circulate but prevents moisture build-up. This is a better solution than using specialist felt, which can get wet and lose its r-value over time.there are a number of vapour permeable underlay products on the market. Some battens are suitable for use with a vapour permeable underlay.
With other battens you will need to add a waterproof membrane under the batten (along with a vapour permeable underlay). This should be installed as detailed below in ‘adding the vapour barrier’ and in conjunction with the eaves venting systems detailed above.at times a building is of brick construction with a pitched roof providing eaves, so it is necessary to create an airflow pathway to prevent condensation in the slates. Also known as an enhanced roof ventilator.
The best vents are those in which the ‘over-fascia airflow’ and the ‘under-felt air flow’ are not connected. This helps avoid any risk of overheating of timber members.a common misconception is that new roofs need extra ventilation and therefore a continuous rafter roll is needed during installation. The reality is that most installation will not require extra ventilation. For more information on how to install a new roof check out my green roof install blog post.
The aim of the counter batten is to prevent water running back to the leeward side. Non-breathable underlay does not need to be counter battened. The position of the first batten should be the batten gauge, plus half the thickness of the batten.
The batten gauge thereafter is based on the pitch of the roof. For example, for a basic pitched roof (12:12), each course has a batten gauge of 100cm (60 cm plus 40cm) and a counter batten is positioned 2 x 12 = 24cm behind this, as you need to include space for the first and second courses at either end.non-breathable underlay needs to be positioned directly below the batten, and then covered with flashing tape. It is best to leave a gap of at least 10cm between the roof tiles and underlay material, meaning that your first course of roofing tiles will overlap the trunk of the scaffold. If you can get some four-way jacks (one per corner) this will give extra support to cover the overlap.batten underlay is the area of a roof, which is located under the battens.
It consists of several components including timber, nails or screws, and is waterproofed prior to installation. When installing this type of underlay, it is necessary to trim down the batten so that the batten falls over one stud.non breathable overlays are plywood or osb panels used to finish the roof. The most common type of counter battened material is a vapor barrier board which is 1/2” mineral fiber with 1/4” gypsum cement on one side and a paper tape face on the opposite side for adhesion.the first step is to prevent heat and moisture from escaping through the roof. To do this, the job requires a non-breathable underlay of 0.9 to between 1.5 and 2 mm thick (the thicker the better) to cover all battens prior to laying the insulation.
Cedar shingles are a natural product and the tendency is for them to cup over time. This not only negates the use of natural ventilation, but can cause problems in later life with snow load. Manufacturers therefore offer “sufficiently high” pitch recommendations to counter this.
While we always aim for natural ventilation on new builds, if minimum pitch recommendations are not reached then it is advisable to add an underlay that can allow some ventilation of the batten space above and below the shingles. One of these products is called vp2, which allows vapour to pass through but stops moisture from passing through and soaking into the timber roof frame. This system works well for two-part roofs, but three-part roofs need.
Step 2b: vp underlay with counter battens. Vapour permeable underlay needs to be counter battened to allow ventilation of the batten space above underlay and below cedar shingles. The position of the first batten should be the batten gauge, plus half the thickness of the batten.
The batten gauge thereafter is based on the pitch of the roof.in rainy regions where the roof deck or the underlay is not necessarily vapour permeable, you may need to create a ventilation space around every roof component in order to ensure sufficient ventilation of the deck and underlay. Opening vents together with counter battens help draw in debris and insects that may otherwise cause damage.in this step we added a vapour permeable underlay with counter battens. A vapour permeable underlay was used to allow the breathability of the space between the transite boards and also to avoid condensation of water on the plywood.
It is important that you set out your tiles fairly but accurately. The first thing to consider is the method of setting out.
Whatever method you choose, ensure you start from a clearly defined starting point. Using either a marking pin or a nail, mark directly onto the roof, and then measure the distance along the eaves for each tile setting and score these positions with the marking pin or nail.the first course is the starter for your wall and the second is the main opener of the game. The tiles are placed with a bonding pattern that should allow you to follow it easily, while keeping the running bond as accurate as possible.
There will also be an overhang of 38mm at the verge. This kind of starter, so to speak, will ensure your brick wall is straight and neat.now you are ready to set out the first course of slates. A minimum of 38mm should overhang at the verge and eaves (two 38mm courses at the eaves), plus 38mm should be left over, in case of cuts needed later during finishing work.
It is also important that the broken bond continues.the crucial aspect of pointing is the weatherproofing. With many flat roofs and low-pitched gables to worry about, this is essential to a sound roof structure. After installing courses, make sure you scrape all excess mortar off the rubble stone and replace with a fresh course.step 3: setting out.
When setting out the first course, make sure there is a minimum overhang of 38mm at the verge and either a 38mm overhang at the eaves. A double course is required at the eaves and a broken bond pattern should be maintained (see fig 8a-d).after leveling the first course and ensuring there is a 38mm overhang, you are ready to set out the blocks for the second course. The blocks should be laid in line from the bottom edge of the first course and level with the top of the steel frame.
The next step is fixing, mortaring or in some cases both. There are a variety of fixes ranging from the conventional finisher that only fixes the apex over to the more modern versions of fixings such as the shinglefix shingle nailer and even fixings specially designed to be used with screw-on underlayment. The choice of fixing depends on several factors such as whether you are spraying a water based treatment or a solvent based one (which would be best achieved using mastic), personal preference and importantly what is most convenient to operate your shingle if you have used a nail gun.once you have all of your kerfs cut and visible butts, you can start hammering down your shingles.
Start at the bottom and go up. This will keep the roof from getting wrinkled and is especially important when using new shingles. If you see a wrinkle forming, quickly grab your hammer and flatten it out. Wrinkles will get worse as you place the remaining courses making it hard to go back and fix them.fixing.
Shingles should be twice nailed or stapled. You can use a 31mm x 1.8mm stainless steel ring shank nail. However a much quicker method is to use the shinglefix staple with a paslode gun.
To avoid splitting and 38mm up from the butt of the course above, fixings should be positioned 19mm in from the edge of the shingle.before using the shinglefix staple gun, make sure your shingles have been laid correctly and that there are no nails showing above the course above. First fix in the lower edge of the shingle using a 31mm x 1.8mm stainless steel ring shank nail. Then use a second nail to fix 38mm up from this point to secure the upper edge.if you are using felt then you can use a pneumatic staple gun. The staples that come with shinglefix are quite difficult to push in and if you have a pneumatic staple gun it is easy to use the special shinglefix staples.
One of the most common mistakes made by roofers is to nail battens to walls. The first thing that happens is over-nailing which can compromise the performance of the cap flashing. This will allow water damage and create a maintenance issue.
The second thing that will happen is premature failure of the first few courses of shingles due to water flowing along the batten and staining them – for this reason you should always maintain your broken bond pattern! These roofs look so good when viewed from ground level and will have a lasting effect on your property value.the outer edge of the narrow-link clip will be positioned flush with the outer edge of each batten. The base of the clip will fit to within 2mm of the roofing felt, drawing the shingle tightly to the batten and preventing any sunlight from entering through air gaps. These small details are what makes a natural roofing system work beautifully.step 6: final fitting.
Once all the shingles have been installed, use a metric spirit level to check the roof is level and adjust as necessary. The batten should be nailed down to the timber tiling with 50mm galvanised nails. When you are satisfied that your roof is completely secure, fill any nail holes with an exterior acrylic filler.nails and staples should be driven at a 45º angle. The nails must be hammered in at an angle of 35-45º without any hammerspace (use the hammer claw to hold it in place).
These are hammered into the roof boards over the battens (battens were previously nailed to the joist using 2a no.8 x 50mm nails). When installing the ridge, mark a batten (at least 20mm x 25mm) to the layout line and nail/secure one side into position using two nails. The nails should be a minimum of 40mm from the end of the ridge and spaced no further than 200mm apart.if you have chosen to use a gutter guard, this should be hooked to battens with small loops running in the same direction. Again using over laps of 200mm, secure gutter guard to battens being careful not to break the batten bond pattern.
Shingles are straightforward to fit. Measure the distance between the edge of the ridge and where you want to place the first shingle, then mark this measurement along your roof line. Get the shingles on your roof, and butt them closely together. Start at one end of your roof, working along from side to side as you add more shingles.
Ensure that the bottom edge of your shingles is level with the butt edge of your first row – otherwise you’ll end up with a lop-sided roof. The top of the last shingle, needs to cover the ridgeline by 50mm, so ensure the highest point is 50 mm above it. Check regularly as it’s easy to make mistakes!. The best type of shingle to use is the ‘jointed’ or ‘cut’ banded variety.
Dont worry about choosing a single or double layered shingle. I would go as far as saying that a single layered shingle is the best bet. The reason behind this is that the roof is going to be be under less weathering / uv stress since it will be covered by other tiles when its finished, plus it will have less weight on top of it.contractors pay a lot of money for the ridgeline – mainly because they want a straight roof and straight-sided roof will give you that. It’s very important when deciding where to put the ridge on your own self-build cabin that you use the same 125mm note as your baseboard.
You will need to maintain the relief in the shingles to keep the current overall thickness of 220mm.siding is applied horizontally, but it’s important to make sure you get the vertical smooth or you’ll end up with ripples and ridges in your final piece. Cut the shingles at a 45 degree angle, and then move them to the vertical position. Cut the bottom row of shingles using a. ridges will be applied to form the pitched roof shape. Shingle roofs have .--------a ridge line running the full length of the roof starting from approx.
30mm out from the gable end. Make sure you are aware that ridge line is not at 455mm (ie half the brick width value).step 5: summits . Build small deck platforms on top of the ridgeline supports. This will support your walkway, so make sure the platform is strong and stable.
Now that you’ve installed your shakes, hips and ridges it’s time to add that finishing touch. Notice i didn’t say roof? You won’t be adding a roof until the top of the hip is installed.
A roof will give you the option of installing regular shingles or installing pre-formed shingles cut in various ways. In my case i’m showing you how to install pre-formed shingles.once the shingles for the ridge row are installed, measure off the next row toward the eaves using a metal roofing gauge. Shingle this row as you did the first, but in this row make sure to stop the shingle course short of the midpoint of the lower roofline.
This will give you plenty of room to install hip and ridge shingles in a later step.the hips and ridges on your roof are the trickiest part of the installation. I strongly recommend you test a patch in an unobtrusive location before proceeding. Both consist of multiple planks joined together. When cutting planks for hips, make sure to allow extra length at both ends for trimming with a miter saw or jigsaw.the last step in the process is to install a ridge cap.
This gives the roof an even cleaner look and provides a layer of protection from ice, snow, and rain. I usually use three or four courses of shingles to give me enough material to cover the hip. I stop cutting about a foot from the ridge for two reasons:.
The next step of shingling the roof is placing the hips and ridges. These are already cut in pre-formed shapes. To cover the entire roof, you’ll have to place a hip-shingle on both sides of every ridge piece. You can also save time by using several short pieces of tin instead of one long piece.