To sark or not to sark under roof tiles – this is a question that many people ask when building or re-roofing a home. Do you need to sark a tiled roof – well technically no – however in some areas its use is mandated due to the new BAL ratings for bushfire prone areas as well as cyclone prone areas. Then there are some councils that mandate sarking and believe it or not it has been my experience that some banks demand sarking use for homes they make loans to.
WHAT ARE THE ADVANTAGES OF SARKING UNDER A TILED ROOF?
- It does give some thermal value.
- It gives added protection for leakage from a broken tile or bad tradesmanship. A broken tile can be a result of walking on the roof or falling branches.
- Will give dust reduction from outside dust.
WHAT ARE THE DISADVANTAGES OF SARKING
Number one the extra cost being between 2-3 thousand dollars on an average tiled home.
Then there is the problem of built up heat being trapped between the ceiling insulation and the sarking – result – condensation.
Condensation – Tile companies will tell you that sarking will help eradicate the problem of condensation. However, this is not the case, by sarking the roof and trapping this heated moist air between the sarking and the ceiling insulation without an effective roof ventilation system is no different than playing Russian roulette with a full magazine. Although the sarking has a gap of at least 38mil in batten thickness between the sarking and the tile covering which would hypothetically take care of the dew point. The dew point explained:- When the inside temperature comes in contact with the underside of the roof covering the heated moist air from inside turns from a vapour into liquid – water – condensation.
A common misconception is that sarking will alleviate condensation however it will more than likely exacerbate the problem of condensation.
CONDENSATION CAN BE A PROBLEM FOR A TILED ROOF WHETHER IT IS SARKED OR NOT
At this point I would direct you to the BLOG on this site – “Very Happy Customer” also “Warning! Read Before You Design Your Next Housing Project”. There are many other blogs regarding condensation and sarking on this site.
If you were to ask my opinion about sarking I would say:- as long as your roof has been professionally installed and there is no mandate to install sarking, keep the extra 2-3 thousand dollars in your pocket.
IF YOU DO OR YOU DON’T HAVE SARKING INSTALLED – GET YOUR ROOFSPACE VENTILATED WITH AN EFFECTIVE ROOF VENTILATION SYSTEM
I repeat effective – Universal Tile Ventilators have the most effective systems for roofspace ventilation and have solved many condensation problems in hundreds of homes due to the over insulation of today’s homes.