Most of you must have heard that slate roofing can be long lasting and also needs much less amount of maintenance. However, how long your roof will last will depend upon what kind of slate you have chosen.
Certain greyish-black Buckingham slate or non-fading green slate may last for 150 – 200 years while softer slates, particularly those quarried in the parts of Pennsylvania have got a life span of about 75 – 90 years.
Therefore, if you intend to replace your shingle roofing with NSW Slate Roofing then you must consider the following:
- Find the source of the slate
It is important to know from where the slate for roofing has been sourced. It will also be nice to know about the location and name of the actual quarry, as few of the quarries have got much better reputation and also offer better warranties.
It is important to look for one who can offer warranty of minimum 75 years.
- Side-lap and head-lap
One of the critical factors is the amount that slates may overlap each other for keeping water out of the house. Slates must overlap minimum by 3” on the sides, which is called side-lap.
Another more important will be the overlap at each slate’s top, which is called head-lap. In case the roof is steep then with pitch of minimum 8” in its height, for each 12” in width, 3” of head-lap is needed.
- Metal on metal
In the slate roofs, copper is the one most common metal that is used but few other options are also there, e.g. coated stainless steel, which also cost less.
Irrespective of which metal the roofing contractor may use for flashing or any other purposes, the actual key is consistency due to something known as galvanic corrosion.
- Choosing nails
Only stainless steel, copper or hot-dipped galvanized steel slate nails must be used as they can last as long the slates will last. Never use electro-galvanized nails as they can rust within few years.
Also, choose right nail which must be double of the slate thickness plus 1”. If nails are not of correct length, then they cannot penetrate your roof sheathing boards.
- Choosing underlayment
Prefer not to use ice/water guard underneath the slate as they don’t allow the slate roof to breath properly and since they are of synthetic material, which is sticky and hence will create problem if any repair is needed.
Rather use organic roofing felt of 30 pounds, which can also protect the home in case there is storm during installation.
- The correct sheathing
Slate can be attached to wood which will be right sheathing material that can also last for 150 years. The wooden boards can be 0.75” to 1.5” thick.
Prefer not to use laminated woods, particle board or plywoods as they are made by using glues that does not last longer.
- Proper equipment and also technique
It is necessary that your roofer must use proper equipment during your project so that no workers will walk on your slate during the installation, as it can crack your stone. So, they must use proper roof brackets.