ᐅ Patio roof over ceramic tiles on a prefabricated house

Created on: 25 Apr 2018 12:16
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ElBoCaDiLlO
Hello everyone,

We have a terrace tiled with 40x120cm (16x47 inches) ceramic tiles, which were installed on 8cm (3 inches) of drain mortar over a 30cm (12 inches) gravel base.
At the time, I didn’t know where or how my terrace roof would be placed, so I didn’t set any separate foundations.

Now I would like to build a terrace roof but face two challenges:

1.) My house is a prefabricated timber frame construction, so the terrace roof must be self-supporting.
2.) I would prefer not to place the support posts outside the terrace on the lawn.

I am wondering if the tiles with this substructure can support the load. The terrace is 3.87m (13 feet) wide, then extends forward with a projection 4.61m (15 feet) wide and 1.2m (4 feet) deep, and then steps back to 3.87m (13 feet) wide again.
The terrace itself is designed exactly like this, with a depth of 4m (13 feet) at all points.
The roof should cover the 3.87m (13 feet) + 4.61m (15 feet) width and, of course, the entire depth of the terrace.

I plan to install two support posts at the wall at the back, attach a crossbeam to the house wall on which other beams would rest. The whole structure would be wood, with roofing made of 16mm (5/8 inch) double-wall acrylic glass.

Attached is a simple drawing.

Handgezeichneter Hausgrundriss auf kariertem Papier mit Innenraumaufteilung

Do you think this will work, or am I risking damage to the tiles?

Best regards
M
meister keks
29 Apr 2018 21:09
Frost-free depth at least 80 cm (31 inches).
For the small canopy, you can use concrete blocks; they don’t cost much but are larger than your 15 by 15 cm (6 by 6 inches) tiles.
Place them in and fill with concrete, done.
Unfortunately, you will have to break some of your tiles, but that way you will be on the safe side.
M
meister keks
29 Apr 2018 21:15
KingSong schrieb:
Why does it have to be self-supporting because of the timber frame construction? We’re also using timber framing, and our patio roof will be attached at the height of the intermediate ceiling, where there is always a big beam anyway. It doesn’t get simpler than that.

You should still check with the house building company, as only they know whether that is possible or not.
If I were to do this with our carport, I would have serious problems with my house.
It depends on what exactly you want to fasten to the house.
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ElBoCaDiLlO
31 Aug 2018 14:18
I need to check in again as we are now entering the critical phase, and I’m having problems with my foundation.
I just can’t dig down to 80cm (31.5 inches). From 50cm (20 inches) downward, there is clay soil, and I can’t get through it. I can only scrape off thin layers by tenths of a millimeter, but that’s it. Even with a large drill and hammer action, I can’t break through.
Does the foundation for standard post anchors need to be below the frost line?
O
Otus11
1 Sep 2018 06:37
ElBoCaDiLlO schrieb:

I just can’t get down to 80cm (31.5 inches). Below 50cm (20 inches) there is clay soil, and I can’t get through it. I can scrape off tiny layers by fractions of a millimeter, but that’s it. Even with a large drill and hammer function, I can’t break through it.
Does a foundation need to be below the frost line for standard post anchors?

Yes, it needs to be deep.
Use a demolition hammer drill (Hilti-class) to loosen the soil.

Tip: A manual earth auger (like those from MWS Apel) or a planting auger can work wonders and is inexpensive. I used the large 300mm (12 inches) version, and it cuts through like a hot knife through butter... The standard 70cm (28 inches) handle is sufficient; extending it to 100cm (39 inches) makes it unwieldy (you end up hitting your own legs) and doesn’t provide significantly more leverage.
A
apokolok
3 Sep 2018 17:22
I also had clay soil and then found a tool called GardenClaw in the basement for the foundations. It worked quite well for that.