CivDesignr Journal

A collection of articles and ideas on construction and maintenance. By Alan Howard BSc. Civil (UWI - Trinidad), MEng. Civil (U of Toronto)
Who I Follow
Posts tagged "Construction"

A Beautiful Australian Home with an insane view. I came across these pics on a forum i follow www.homeone.au and fell in love with the design. See more great pics at http://blog.chuq.net.

How can good surface preparation help with Painting

Source: http://www.homedit.com/eco-friendly-wall-paints/

(Source: http://www.homedit.com/eco-friendly-wall-paints/)

Some time ago I mentioned how important it was to have a good surface prepared before placing any construction material (Surface Preparation Post). 

One place where surface prep is important is painting. Most home owners have painted a room before and this is one area where surface preparation can help improve the quality of the finish.

If you are painting a raw wall in concrete or drywall priming the wall is a good place to start. But even before priming use rags to remove any dust or dirt on the wall. Do this to allow the paint to adhere to the wall instead of adhering to loose dirt on your wall.

With a clean wall your next step should be to protect any surfaces that should not be painted. All wall sockets, base-boards and other surfaces should be taped and a drop-cloth placed on the ground to protect your floor. At least one coat of primer should be placed on new walls in order to seal the wall and enhance the bond between the new paint and the wall all while preventing the wall from sucking up all your paint.

To calculate how much paint you need you can use my paint calculator here.

Some beautiful Ceiling panels put up by an australian company http://www.perthplastermouldings.com.au/

How a short term fix becomes a long term solution

(Image Source: http://tiny.cc/1qkzcw)

As I was driving home today I saw a house with a typical split system unit. The indoor portion (evaporator) of the unit had all the lines running through a hole in the window back to the outside portion (condenser).

Seeing that made me wonder how a situation so obviously “makeshift” could have become a permanent solution to a problem and I remembered all the conversations i’ve heard consultants and contractors have over the years about how soon they would “get back to that” and “this only temporary” only to find that years down the road the temporary solution was lost in the crush and no-one got back to it.

Never let a consultant/contractor on a site push temporary fixes as a way to “put to bed a thorny issue” or brush aside a concern. That little extra effort to make a permanent fix in the first instance will pay dividends later in your project when you realise you don’t have the time or energy to enact the permanent fix.

How should I manage the change process.

(Image Source: http://tiny.cc/8tkzcw)

I was reading a forum online about a home owner in Australia building their new home with a good process to manage changes in place.

However, things still went wrong. The client requested a number of changes, the contractor submitted updated drawings that were approved by the client BUT the drawings didn’t have all the requested changes.

Here is a copy of the post in question and full forum thread:

Thanks alot of the help guys. I have since released the progess payment to them in good faith before this was fully resolved, though now things have just become a bit more interesting. As since signing the final contract drawings, which had the eaves going all the way around the house. The builders then asked me to sign a new drawing designs plans for a variation to our driveway. However unbeknown to us and under no instruction, the builder also changed and took the eaves off the side section of the the house in the drawings. 

So would the builder be able to say that I’m liable to pay for alterations to put the eaves on and to make the house compliant with the estate covenants? even though in the variation letter/request which only details changes to the driveway and makes no mention whatsoever of the eaves. And just that by me signing a later design drawing plan, it’s my fault for not picking up on their mistake, or is it that because there’s no mention of the eaves in the detailed variation letter, that the eaves should have been built according to the final contract, and not the later signed display drawings (especially given that I was only looking for changes to the driveway in the new drawings as per the variation letter)?

Any help would be greatly appreciated as the builder is putting everything on the basis that they’re just going off the drawing plans that were signed off after the initial final contract binding ones, even though there was no variation letter/request for those changes.

Ultimately I agreed with the guys on the forum. Quickly correct your mistake and restate your position. You as client can’t catch all of your contractors mistakes and they really aren’t your responsibility.

Really, the lesson here is to take your time when reviewing changes and act quickly if you make an error.

One other factor to consider with changes is thinking them through before enacting them. Mull them over, discuss them with your contractor or anyone else involved in your construction decision-making process, make sure that the change is what you want. You need to do this each time because all changes have implications on time and cost and you need to be aware of what you are getting into beforehand.

Changes will always happen on every project; they are part of life. Having a good process to manage them is essential to a successful project.

How to Deal with Changes in Structure

(Image Source: http://tiny.cc/rwkzcw)

The “structure” in a building can be considered equivalent to the bones or skeleton of the building. The structural components are those parts of the structure designed to keep the building up.

Like the bones in your body from head to toe there needs to be firm connection from foundation to roof in the structure.

Aspects of renovation which require changes to structure therefore must be carefully considered, planned and executed. You should engage an engineer or a contractor with engineers on staff when dealing with major modifications to your structure.

During the planning phase the engineer will advise the contractor of how final structural modifications will look like and ALSO what the structural modifications will look like during the construction phase. It is vital that this second point isn’t overlooked because the contractor can’t just cut structure without making sure that structural loads are properly transferred during the construction phase. Failing to do so can lead to dangerous structural settlement or worse a collapse.

Liability in Construction Contracts

Buck Stops Here sign

(Source: http://www.trumanlibrary.org/buckstop.htm)

Who is responsible? where does the buck stop? where does it all end? These are all important questions to be answered before entering into any contract with a builder or consultant because having clear expectations at the start of any project is a sure way to avoid disappointment later.

Liability or Responsibility should be placed squarely in the lap of the person best able to deal with the associated risks. I have discussed this before in a previous post however the reality of liability extends beyond the terms of the contract. The safety of persons on the site is one such liability shared by both the home owner and the builder. For example, a home owner shouldn’t knowingly allow a builder to run an unsafe site and a builder shouldn’t know better than to run an unsafe site as well.

Since this liability exists and since the contractor is in charge of the work on site then damage caused by site accidents should be covered by the contractors insurance instead of being passed on to the home owner directly. As a client, the home owner should therefore make sure that all necessary third party insurances are in place to prevent this.

How moisture can affect your building 

Source: http://amarkedman.com/wp-content/uploads/2011/03/Condensation.jpg

Water, one of the most plentiful substances on the planet, can wreak havoc on most building materials. It is a requirement for living things and its presence usually brings some sort of flora or fauna. While most building materials are affected by water those which are based on natural materials generally more susceptible to water damage. 

Since building envelopes are meant to protect its inhabitants from unwanted environmental effects designs should either keep water away from materials sensitive to water or provide an easy way out should water get in.

In cold climates the importance of keeping the water out of a building is greater because of the likelihood of condensation. this can occur inside the wall or on its surface and can degrade the material or worse still foster mould growth on the surface and it is believed that the toxins associated with certain moulds can cause negative health effects.

A common way to prevent unwanted water entering is by using plastic (polythene) sheeting. Placed under a floor or in a wall it is an effective way to stop unwanted water. Care must be taken however to prevent holes or punctures in the sheeting or its purpose may be defeated because moist air or water can get through the holes. Sealing the edges is also important for the same reason.

The location of sheeting is important because we don’t want to trap water in the wall or floor by putting the sheeting in the wrong location. In walls the sheeting is placed closest to the warm side. Why? Because condensation is formed by the cooling of warm moist air. By keeping the plastic on the warmest side we keep the moist air warm and prevent it from getting to the cooler side of the wall and avoid it cooling enough to cause condensation.

Steel - What should a client/homeowner know
Source: http://rodtechs.org/yahoo_site_admin/assets/images/310207184_c8d55d23a4.187194824_std.jpg
Steel is not as common as wood or concrete in a typical home but it still plays a vital role in ensuring the  structure remains standing and aesthetically pleasing. When left exposed to the environment steel rusts/oxidises just like its parent compound,iron. Rust doesn’t have the same strength as steel so when steel turns to rust/oxidises and it changes the thickness of the member this can affect its strength. This doesn’t affect very large pieces of structural steel used in buildings. This is because when rust forms on steel it actually isolates the steel from further rust by creating a protective layer. This method of isolation is especially true of aluminium because the oxidised layer of aluminium is thin, forms almost instantly and adheres strongly to the pure aluminium below.

On site reinforcing steel forms rust within a few days of being exposed to the elements. smaller diameters of steel (#3, #4, #5 and #6) which are typically used on houses should be protected since they are so thin that rust will easily compromise their strength. larger sizes >#7 form rust as a protective layer and can be cleaned and used even if they are rusty.

After reinforcement has been placed in concrete rust can cause cracking in the concrete. This is caused because rust is larger than steel and when steel converts to rust the member also expands and pushes the concrete away causing cracking. 

Rust can be prevented by ensuring that the reinforcing bar is protected by its environment. One way is making sure that the steel is properly embedded in the concrete. This is especially important if the structure is near the ocean or underwater because these environments can accelerate rust. A registered engineer or an experienced contractor can advise what level of embedment is required.
Wood - What should a client/homeowner know


As far as natural products go Wood is the most common natural product used in construction and its warmth and variation in texture make it popular especially in homes. While wood is widely popular it is a natural product and reacts to its environment. Water is the environmental agent which has the biggest impact on wood products because it can cause wood to change shape and bend. To avoid this one should avoid taking wood from a humid environment and putting it in a dry environment or vice versa without allowing the wood to acclimate to its new environment. large kilns are usually used to change woods moisture content when taking it from a wet environment into a dry one. If you don’t do this the wood could bend and warp after you put it down.
Wood is also susceptible to attack by termites and other pests. Pressure treatment of softwoods is used in order to avoid future damage to the structure. In this process the wood is soaked in a pesticide and placed under pressue to force the treatment through the entire wood member. this ensures that the treatment is more than just “skin deep”. Structures in a tropical climate where winter cold does not kill insects should ensure that all wood used is pressure treated.