One-Sided Roofs (Shed Roofs)

Daniel here. Was looking at roof designs yesterday for a friend’s extension. He wanted “modern” but I was worried about typhoons. Ended up looking into shed roofs (skillion, mono-pitch, whatever you call them).

Actually… they’re pretty good?

why they work

It’s just one slope. Simple.

• less seams = less leaks (usually)
• you can pitch it steep to shed water fast
• looks clean

But the wind… that’s the scary part. If a typhoon hits that high wall side? it acts like a sail. You need to be careful with the overhangs. Saw a house in Bicol lose its entire roof because the overhang was like 1 meter. wind just grabbed it.

making it typhoon proof

(or resistant, nothing is proof)

1. The Pitch Keep it 30-45 degrees. If you can, point the low end towards where the wind usually comes from. idk how you predict that perfectly but check prevailing winds in your area.

2. Straps are cheap, use them Hurricane straps. They cost like 50 pesos? maybe less. Contractors skip them because “nails are enough sir”. Nails are not enough. Buy the straps yourself if you have to.

3. Short overhangs Keep em short. under 50cm (20 inches). Yes it means less shade for the windows (buy an awning) but it keeps your roof attached to the house.

materials matter

Use metal screws, not nails. And check the gauge of the roof. Gauge 26 is standard but thin. Gauge 24 is better. If the supplier tries to sell you Gauge 28 just walk away. It’s tin foil.

vs other roofs

• Hip Roof: Still the king for typhoons. aerodynamic from all sides.
• Gable: okay but that flat triangle wall takes a beating.
• Flat Roof: leaking nightmare usually.

anyway shed roofs are fine if you reinforce that high side. Just don’t skimp on the trusses.

prices for trusses went up recently too… but that’s a rant for another day.