CivDesignr Journal

A collection of articles and ideas on construction and maintenance. By Alan Howard BSc. Civil (UWI - Trinidad), MEng. Civil (U of Toronto) var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-30900634-1']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })();

[civdesignr]

Tile Underlayment - How to make your tiled floor last longer

Tile Surface Preparation Materials

(Source: Schluter-Ditra)

A few weeks ago I did a post on surface preparation. In it i pointed ou tthe importance of making sure that your surface is clean and prepared according to specification, and also making sure you use good materials.

One such material is Schluter-Ditra from Schluter Systems.

It is lightweight, and acts to both prevent cracking and waterproof the tile floor. Prevention of cracking is important but waterproofing is also vital to protect both wooden sub-flooring in wet environments.

Ditra also can reduce vapor pressure on the tiles above. Vapor pressure arises when moisture in your floor tries to diffuse into the room space above. This creates a pressure on the base of the tile which can cause it to pop up over time. Since Ditra is a plastic sheeting it acts as a barrier to the moisture thereby eliminating vapor pressure.

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Hurricane Resistance - Walls

Source: Miami Herald Hurricane Preparation Guide

Following on from my last post on construction for hurricane protection I have a few more tips but this time for wall construction using concrete blocks (concrete masonry units - cmu). 

This type of construction is very common in the Caribbean and southern Florida due to the higher hurricane resistance of this type of construction.

In order to ensure that your hurricane resistance is maximised first and foremost a qualified structural engineer should work with your contractor to confirm proper practice is adhered to. As a client however there are a few things you can look out for as major red flags.  it is vital that your roof structure is properly connected to your walls. This is usually done using a capping beam and reinforcement in the block holes approximately every 4th block hole in non loadbearing walls and in each hole for walls carrying heavy loads. If this is not the case on your site ask a question of your contractor and/or your engineer. 

Your wall reinforcement should continue all the way to the foundation and tie in correctly there as well. It is also good practice to include stirupps in the corners and wall intersections and to reinforce and pour all block holes in these areas. This will cause your corners to act like columns and bring greater stiffness and strength to your structure. 

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Pretty but... practical?? :-/

modern bedroom design by new york architect Jordan Parnass Digital Architecture

[civdesignr]

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.

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You gotta be kidding me. This is so good.

Kaffee Partner Headquarters ...see more on Architizer

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House on the Bluff ...see more on Architizer

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Paint Surface Preparation

How can good surface preparation help with Painting

(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.

[civdesignr]

“You can get it fast, good, or cheap. Pick any Two.”

How fast should your project progress

I first heard this line in a class at university on civil engineering materials and my lecturer was relating how important material selection was.

In my working life, however, I have realised that Engineers, Contractors and othe building professionals have a perception that people want evertything fast good and cheap all the time but this is a misconception.

What some professionals don't realise is that most home owners:

a) know that they can't have everything and

b) really do want the best end product.

All they need is the knowledge and that is what the builder should provide.

This may seem a bit silly but a good building professional should be like my favourite and current dentist.

She makes my visits so easy to deal with because she keeps me in the know. She lays out what is going on and my options and what the costs are. While she is working she lets me know what is happening and what decisions need to be made along the way.

Most home owners are willing to pay a little extra to secure their investment. If they don't take the option you present at least they know the risks and consequences. And this makes for a happier customer in the end.

Which two would you pick?

[civdesignr]

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

[civdesignr]

How much concrete is needed for a floor slab that is 10'x 20'

To determine the amount of concrete required (or any of the materials that make up the concrete) we start with a calculation for volume.

A typical ground floor slab cast on solid ground (cast "at grade" in engineering terms) is between 4 and 5 inches thick or between 100 and 125 millimetres in metric.

Assuming a 4" thick floor first convert everything to feet and multiply length x width x thickness.

Volume of Concrete = 20' x 10' x 0.33' = 66 cubic feet

You can also Try my Concrete Material Calculator on my calculations page here which can determine how much cement, sand and stone in cubic meters you would require.

Also bear in mind that a 94lb bag of cement holds 1 cubic foot (0.0281 cu. metres)

Here is a sample picture of my calculator below.

                     Click HERE to use calculator shown above

[civdesignr]

Temporarily Permanent

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.

[civdesignr]

Managing Change

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.

[civdesignr]

The Importance of Structure

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.

[civdesignr]

Who watches the watchman

Avoid Site Supervision Pitfalls

How can you be sure that the workmen on your site are being productive and giving you value for money? Should that cabinet really take 2 days to install? With the high costs of labour nowadays every hour affects "the bottom line" and clients are justified in being concern about effciency.

The key to ahceiving efficiency is choosing a good on-site supervisor. Most workers will fall in line behind a good no nonsense site supervisor but how do you find one?

1. Past on time performance is a good indicator of how well a supervisor will perform on your job. Ask questions about past customers and whether projects ended on time.

2. If you are in North America check your local better business bureau (http://www.bbb.org) or equivalent agency in your area for information on your builder and his past interactions with clients.

3. Beware if your contractor is a one man show. Progress should still occur if the "main supervisor" isn't there or is sick. 

4. A good site supervisor plans. He should know what will happen if he is not there and he must have a second-in-command if he is not there.

Keep these key tips in mind for a project which progresses as it should.

[civdesignr]

Where Does the Buck Stop?

Liability in Construction Contracts

(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.