Beware of clay soils in Philippine construction.

Beware of clay soils in Philippine design.

Coming from a put where by it will get incredibly chilly in the wintertime (Upstate New York), we realize that footers have to be deep enough, usually 4 or 5 toes, so that freezing soil does not heave and harm buildings.  When we built our home in the Philippines, we puzzled more than our engineer’s ideas which termed for column footers to be a few or 4 ft down below the first degree of the soil.  Why in a position wherever it never freezes do footers have to be so deep?  Likely such deep footers are not vital in several areas of the Philippines, but our property is underlain by numerous ft of extremely dense clay.  This is normal of “rice land” in the Philippines.  If you have sandy or rocky soils just disregard what we say, but of course you may well have unique building troubles.

As pointed out, our region has major clay soils dozens of meters deep.  All through the dry time these soils crack and shrink. This shrinking and cracking can exert large drive on buildings not supported by deep foundations —  foundations properly beneath the region influenced by the seasonal shrinking and expanding of the clay.  Only constructions with footers deep more than enough to be steady will escape these forces.


Soil motion by shrinking clay can tear apart concrete development. These cracks can lengthen a foot or two or a lot more  below the floor.

We have had an extremely dry summer in 2016. We first acquired of the dangers of shrinking clay when the charming concrete system our workers crafted for us close to our nicely and water pump was damaged aside by the heaving clay beneath it.  The basis of this system was a person hollow block established on edge and a concrete footer The cavities in the block were stuffed with concrete.  Reinforcing bar tied the aspects collectively.

Concrete platform around our well and water pump.

Concrete system all over our very well and water pump.


As you can see in these shots of the platform’s demolition, it was not frivolously designed. Even so, it was destroyed about its five year lifespan by the seasonal growing and shrinking of the soil on which it sat. Our employee is shown breaking up the system. For the time currently being, the platform has been changed by topsoil. The nicely by itself was not influenced as it extends some 25 toes into the floor and as a result is well supported.




Here you can see a lovely tiled concrete stoop currently being eliminated. It was extremely strongly manufactured of 1-2-3 concrete with rebar. It was not destroyed by the clay soil, but it experienced no under quality footers and moved with the shrinking and growing clay soil which was beneath it. The motion f the slab  threatened the numerous water and drainage pipes functioning underneath it.  That’s why it had to be taken off. Constructing on a slab could be fine on sandy soils (Florida?) but do not seem suitable for the shifting clay of Philippine ricefields.

Catch Basins.    Our dwelling has an interconnected  system of underground concrete capture basins which accumulate h2o from the roof and gray drinking water from the bogs and kitchen and direct it away from the dwelling so the area all around the dwelling does not become soaked, muddy or worse.  The catch basins themselves are extremely solid but as the clay soils dry out and shrink, the catch basins sink.  When the rains occur and the clay soil expands, they shift upwards once more.  As you can think about, with plastic pipe connecting the catch basins to the house the home steady, the capture basins going, pipes can do do break, but they are underground so you might not be aware of what is taking place, but this photo exhibits the impact of sinking catch basins on gutter downspouts.










But the major party is the destruction of our storage constructing by these forces.

After the home was finished we had some big roof trusses remaining over owing to an engineering improve. (A transform we by no means comprehended.) We also experienced some 16mm rebar remaining about. So, we determined to establish a shelter for our car.  We seriously did not have right plans, but we went forward and constructed four big columns which supported concrete beams bolstered with that leftover 16mm rebar.  Then we took the leftover trusses and applied them to make a roof construction which we subsequently roofed with the exact same metallic roofing we used on the property.

The garage columns had proper footers and have not moved.

The garage columns had good footers and have not moved.  Disclosure – this is a footer from the residence.  We did not have a photo of the garage footers.  They were being the exact same.


Garage frame up and completely ready for roof trusses.

The leftover roof trusses were sized for the home, not for the substantially more compact garage but I was loathe to cut off the ends of the trusses.  The oversized trusses permitted larger area secured by a larger roof — for “free”.  We did reduce the finishes of the trusses on the facet of the garage demonstrated below, but left the truss overhangs on the fence facet of the garage  This gave us a garage which was substantially also substantial for our single auto.  At that position the garage flooring was just gravel.clay_soils-1-6

clay_soils-1-7Why not use the further place for a a great deal-wanted storage space and a modest laundry spot?  All the things was impromptu at this level and that was a oversight. The garage making alone has deep footers and has been entirely steady, even nevertheless some compact earthquakes.


Storage and laundry spot staying extra into more space underneath garage room.


Accomplished storage place with iron doorway.


and laundry region



























However we did not set in correct footers and columns for the storage area.  As a final result the rear wall of the storage place/laundry are has sunk a number of inches and is tearing aside the storage location.


What you see here on the right is a person of the garage columns which is resting on proper footers. On the left you can see that the rear of the storage room  is sinking, pulling the total storage room construction aside. The entire developing will have to be demolished and changed.


At the time we designed this area, we did not see the have to have for the deep 4 foot footers we used elsewhere.   This “shortcut” will value us dollars in demolishing the previous composition and in building a new a person.  Had we taken the time to put in even two columns on suitable footers, the building would likely have served us for several several years. Lesson:  use an engineer to be certain what ever it is you are creating has correct footers!


Despite the challenges, the garage is wanting excellent.