General Building Questions

[jeff bradshaw]

Hello. I am in the process of designing our home in Calatagan (Batangas) and have some general questions.... 1. We will be supplied with a single phase supply and I will be installing an earth bond system with maybe three spikes driven around the property. I have seen some references where people bonded the copper earth spikes to the Rebar buried inside the concrete walls and floors of the house. Is this general practice as I have not come across this before? 2. We have purchased the land from Landco and part of their 'Deed of Restrictions' states that the Shower drain, Washing machine / washroom, Sinks and any area that is likely to receive detergents such as a carport, should be connected to the Sceptic Tank along with the Toilets. I may be missing something here, but I had read somewhere that the Effect of detergents was to break down the bacterial action necessary for the Sceptic tank to function properly? Whilst I understand that a separate Grease trap would be a benefit on each of these areas...is it correct to connect them to the sceptic tank? They have conceded to allow me to connect the output of my tank to their Sewerage treatment plant instead of needing our own drain field, so the emphasis on my tank will not need to meet the full local environmental levels. I am challenging other areas of the sceptic tank design directly with Landco, but they have specified an 8 cu.m (8000litres) 3-chamber tank. We are building a 1-bedroom small beach cottage for just the 2 of us, and think it is overkill reading that 1000litres is suffcient. I have also been looking at some modern single bin pre-made type designs by Bestank, Inca and Weida. all claim to be more efficient and smaller. Does anyone have any experience with these compared with the conventional concrete design? 3. Finally. Being my first home build I am sure I will over-engineer the whole project based on so many scare stories and my own observations about Philippine standards of build and the need to make it typhoon and earthquake proof (well, as best as possible). One source recommended using coated rebar throughout instead of plain steel to avoid the long term rust issue. I haven't checkout the extra cost of this, but have never actually seen anyone using it in the 3 years I have been here. Is it really worth the extra cost? Regards Jeff

[Dave Hounddriver]

All interesting points. First, I have noticed that there are 'experts' in the Philippines from many different countries, all with different ideas about what is the only correct way to do things. The results have always fascinated me and I am highly unlikely to ever buy an expat built home here, unless the price is extremely fair to the purchaser. Your idea of tying the ground rods to the rebar has been done by a few expat builders that I know. The ones that have done it swear that it works and the ones that have not done it swear that it does not. I tend to believe it can't hurt but the connection of the copper to the iron will likely rust away over time. Others have used metal plumbing and tied the ground to that but again I have noticed a lot of premature rust in the plumbing. Rust is a major problem here. Personally, I will tie the ground to the rebar. What can it hurt? At worst you will have a poor ground like most of the other homes here. About the septic tank, I think that is a city vs rural thing. In Cebu and other big cities, (and maybe some suburban subdivisions?) there is a code that tells you exactly what you must build for septic. Does everyone follow that code? I doubt it, but the system you describe is code in Cebu. In the province you will find tanks with one chamber and no bottom so the liquid will leach down. Again in the province, what I commonly see is a two chamber system and grey water not connected to the sewer (as in just draining into a nearby creek or dry well). Discuss it with whoever will need to sign your permit to see what you can get away with. The coated rebar? I've never seen it. Maybe you could start a trend. I see many buildings that are countless years old that still have the rusty rebar rising above in preparation for the next story that will likely never come. About being typhoon resistant, the best advice I have heard is to use a 'hip roof' design rather than a gable roof.

[Old55]

I am not an expert.1) Yes, your service drop will be supplied with a single “hot” and a single “neutral” leg the box may or may not have a ground. That is the only safe true ground. If the energized leg were to be exposed to neutral the breakers may not trip but if to the box ground the breakers will always trip. IF you were to have GFI at the box the breaker would trip if hot hits neural this can be done in Philippines.You may use an earth ground like you describe but the results may not be as effective. 2) Can not help you. Be aware mosquitoes and flies can move up drains from cesspools into your home speak with the builder to engineer this out as best you can.3) The important thing is to avoid counterfeit rebar as much in Philippines is not what it seems but Chinese or local counterfeit junk.

[jeff bradshaw]

Thank you for your quick replies. I guess that I have to be realistic and go with gut feeling. I spoke to some other expats recently who's house was double the cost to build from my quick estimate, having seen plenty since living here, but they were happy. The building company would hop in a car from Manila every time there was a simple fault to rectify. My guess was that they were feeling so guilty for having ripped them off so badly. It is easy to follow everyone's advice based on what they feel they should have done better, but it always comes down to cost doesn't it. The typical expat house is a veritable fortress of the latest imported engineering standards and belt and braces tactics. My filipina wife keeps pointing out to me that the majority of houses built with old techniques and dubious construction methods are still standing, defying all of our logic. True that some crack and some collapse, but then again they are subject to more severe weather issues here than our respective countries. We sat in a bar in Boracay this evening and studied the bamboo roof, which was as solid as you could expect, and showing no sign of collapsing considering we just got hit by a typhoon. I have to battle with my protective instincts over the next week as all of the input I have had from the many helpful sources have left me with a mass of notes to incorporate into the drawings I will supply for the build. What to put in...what to leave out...Cost versus risk being the bottom line..... Thanks and bye for nowJeff

[jeff bradshaw]

Another point I didn't reply to...I am aiming at a 'Polynesian' style roof, which is sort of like the Dutch gable, but with the upper section sloping at a greater angle than the lower. I know that this introduces some extra windloading, but I will try to balance the aesthetics versus the angles of the slopes. I have also been looking into a modern version of the wooden shakes as I didn't want to go the metal roof route, or the heavy weight of concrete tiles, and as we are aiming for a tropical feel to the styling, I hope it will look better. CPAC Monier seem to produce the roof material I think I will use. Anyone got any experience with them, or the design and build of one of these types of roof? ThanksJeff

[Dave Hounddriver]

I have also been researching and tentatively working on a building project. I am taking it slow and using the local methods anywhere I feel it will do little or no harm. Its how they know to build and that is the cheapest way. BUT, as you said, every time I turn around things cost double what my original budget was. One big frustration is the 'out of stock' syndrome. You will price out an item and then, a month later when you go to buy it, it is out of stock and the competitor wants 25% more than the price you budgeted for. All in all it is fun if you are not in an urgent rush for a roof over your head and you can be flexible.

[jeff bradshaw]

So far I have been building up a list of reference prices from the major suppliers like Wilcon, Home Depot and other local ones based on what I would expect to be Better quality. I will then compare what quality and price is available at the more budget local contractor allowing for delivery costs and see what happens. Sometimes a little extra cost for the convenience of easier delivery arrangements and guaranteed availability is ok. I am also looking at leasing some space near to the building site so that we can get as much as possible ordered in advance ready for use. Our lot is only 253sq.m and slopes, so cannot rely on storing much on the site during construction. I am trying to go for poured concrete instead of CHB for the major structural elements and will get a professional company to quote such as Sibonga along with a local contractor. The majority of the design I am doing myself...ex-engineer syndrome as usual, but I was a senior design engineer in the UK broadcasting industry for many years, albeit not in construction, so I trust my own instincts and design experience rather than someone elses. As a sanity check I will make sure everything is checked by a proper structural engineer though as that will be part of the building permit application process and want the insurance of a sound foundation seeing as our lot is on a steep slope, and needing to make the best efforts at typhoon and earthquake resistance. The cost is the one thing which seems to cause plenty of disagreements. My wife, being a native puts the cost of our house (excluding the perimeter wall and landscaping) at 700,000 peso total building costs, based on me doing much of the joinery (used to make quality furniture as a hobby and qualified in stained glass work), electricals (was a qualified electrician in my early career...full apprenticeship in the UK) and as much of the plumbing as I can manage, so mainly the structural elements and roof being contracted out. I think it is a dream, and more likely to cost double, but it is a 2-level 48sq.m design buried part way down a slope, so we will see over the next few weeks as I start to get the quotes together. For reference, we are buying prepared to size capiz shell and making our own windows and doors, maybe using a local woodyard for the machinery and labour. I might get a carpenter to lay out the stairs as we are planning on using lots of wood and getting a good deal on bulk quantities might be easier if a company is also doing some of the labour. My wife's family are from the province and have many contacts for the stonework, landscaping materials and such, so we can keep the cost down there. Fingers...and legs crossed then !!!! Jeff

[Dave Hounddriver]

My wife, being a native puts the cost of our house (excluding the perimeter wall and landscaping) at 700,000 peso total building costs

The reason my wife underestimates, and yours may do the same, is twofold. First she bases any estimate on what someone did 4 years ago and prices of some construction materials and labor go up very, very fast here. Second she does not want to put me off building and she thinks if she underestimates and we have to pay more later it is better than overestimating and deciding the project is too expensive. That and she does not have a clue how to do a realistic budget although we have gone over it many times.

[jeff bradshaw]

I think you are right, and the only way around it is to do your own investigations and allow plenty of contingency. Location makes a difference and whether you trust the local companies who may only ever have built the normal homes, with the not so careful methods, covered by the final cosmetic touch-ups that hide a myriad of problems for the future. The biggest worries I have is the continuous warnings about how to treat Filipino workers and how sensitive they can be to adverse comments about their work. My wife thinks she will be playing mediator most of the time, Trying desperately trying to stop me wanting to kill or dismiss them for shoddy work or being held to ransom when they walk off site with a part finished house. Well, The alternative as we now have the land is to pay an exorbitant price to have someone build it for us and almost certainly be dissatisfied with the result. I will try to explain as much as we go about what I expect and plenty of example photos as to what they are aiming for along the way and try to stay calm and friends with the foreman when we choose one. So far I have been working on 4,500peso per day for a 10man team, Fading out as the labour needs reduce. We will provide them meals during the day with a mobile kitchen...i.e. my wife! This should be more than enough. I will aim to minimize the losses due to things going astray when they want me to go off-site continually to fetch and carry so they can slip in a shortcut or slip out a bit of a freeblie! One of the problems is the lack of quality materials locally and the need to go great distances to get good stuff, especially when it comes to the fitting out. The 2 months before starting to build will be a major shopping spree and storing it, buying as much as possible and not leaving the contractors to buy anything other then what they need for the formers for the concrete work. Gonna be fun I think. Jeff

[jeff bradshaw]

Another question about septic tanks... The normal design of a septic tank includes air vents. The criteria for my design was laid out by the land company Landco to be a 3-chamber 8cu.m design. They have agreed to me connecting the outlet pipe direct into their sewerage system, thereby not needing our own drain field. I have included for an air vent outside of the tank in the Inlet piping, but not sure whether to include one in the 2nd chamber. Surely most of the gases will have escaped by then? I do not plan to fit an air vent in the outlet pipe as I do not want Landco's system feeding gases back up my pipes and polluting our garden with odours. On a similar but separate note...It seems to be common practice here run all piping inside the support columns for the house. This obviously poses questions about any leaks should they occur. Considering the volume of rainfall during typhoons it seems risky. A recent house build close to us has 100mm drain pipes through its concrete structure, making the columns enormous for the size of house. I think I can engineer the columns to be big enough to not affect the structural strength too much, but is it good practice anyway? The layout of our site will mean that the septic tank will be close to the house and it would be convenient for me to route the Inlet vent pipe into the nearest concrete column and out through the roof. As this is only carrying gases and not water, is this ok? My other concern is that we have a room build into the roof with surround windows and it would be ugly to fit the vent pipe through the nice roof and possibly cause us odour problems when we open the windows. Are there alternative ways of doing it in the Philippines? ThanksJeff