Expert: Bruce E. Johnson - 10/6/2009

Question
Good day Sir,
I am a young civil engineer bu there is a problem perculiar in my environment. The water table is high and any building built have soaked walls in no time. the paints peel off and the walls become soft. How do i take care of this now and in the near future? I also want to know the various steps taking in building a house. Thanks

Answer
Hi Idahor, this is a problem with concrete or masonry.  In order to be externally waterproofed the concrete needs to cure completely and be dry prior to the application of paint. To keep water away from a building in a high water table area you need to use pumps to keep the water table dry. If you are talking about basement construction then you can stop water penetration with bitumunous products, mastic, or fiber reinforced mastic.  However it is essential that a footing drain be installed to keep the water away from the foundation.  A typical footing drain consists of crushed rock or river rock in a layer one foot deep with a perforated drain pipe or drain tile system on top of that with another 12" of rock over that followed by drain field paper or cloth.  The pipes are run to a lower elevation to drain or into a sump and then pumped out.

There are methods of mixing waterproof concrete using air entrainment, latex and other additives.  You  would have to see what is available in your area. Some commercial sealers can provide a penetrating waterproofing but the most effective ones are silicone based and thus can't be painted over.

As far as house construction..any construction for that matter.  You have to start with a good foundation.  It can be a monolithic slab foundation, a stem wall with footing foundation, a post and beam foundation..this is then followed by a floor system except in the case of the monolithic slab which integrates the floor system into the foundation.  Floor systems are either joists or beams depending on the sub floor material and are supported by the foundation.   Once your floor system is in place then you build up your supporting walls..In masonry construction your walls can either go on top of the foundation with a floating concrete slab interior or they can sit directly on the monolithic concrete slab footing.  Your masonry walls are reinforced to withstand lateral forces and topped with a concrete tie beam or two course concrete filled masonry beam..In the case of wood wall construction the walls are tied to the foundation in various ways depending on your local requirements.  Then you top your walls with a roof system, either engineered trusses or hand framed rafters.  This is followed by your roof sheathing and shingles or waterproofing.  

In the foundation stage you should also be installing underground utilities such as plumbing, electrical and any below grade HVAC requirements.  These elements will come out of the ground with your building and follow through to the final completion..

As a young aspiring engineer I strongly recommend that you obtain a copy of Architectural Standards..This is a must have book which covers just about every building type and element.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com