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Concrete block vs. other building materials

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As long as there are entrepreneurs there will be new products available and sometimes something new makes sense but perhaps it may not be practical for cost or availability reasons. Unless you have lived and worked in Costa Rica, one thing you wouldn't realize is that transportation to the beach and mountainous communities can add considerable cost and time to your project. So any new products that are not distributed throughout the country by the major building supply companies will be a hassle to get to the building site, on-time and within budget.

 

Wood for instance, as the primary building material for housing construction is not practical here in Costa Rica for several reasons. We are here in a tropical, humid and heavily forested country, approximately 10 degrees north of the equator. A prudent and responsible builder needs to factor in the effects of the suns rays and excessive humidity as well as the seismic activity and pest infestation into the selection of building materials here.

 

Also available are the pre-fab concrete wall and post building packages. I know an American of Latino descent who has lived and worked here for many years who bought one of these home packages years ago and he had a lot of additional time and expense with finishing the walls to look decent. Their system uses concrete structural posts that are inches thicker than the thin wall panels that fit into them. The pre-fab walls and posts still need to be plastered with concrete to complete the home. Those systems are only good for storage sheds or other structures that do not need to be finished smooth to look like normal interior and exterior walls.

 

Based on my 15 years experience here in Costa Rica, the best product to use from a cost and construction standpoint is traditional 40x20x15cm block with 3/8" and 1/2" steel re-rod for vertical reinforcement. Traditional concrete blocks have been used by builders around the globe since the beginning of time and more recently to build Habitat for Humanity homes throughout the world. The blocks' convenient availability and ease of lifting was the selling point for the Habitat projects, as they are dependent on volunteer labor. These traditional blocks are all 40cm long and 20cm tall with three variable widths of 12cm ($.51), 15cm ($.64) or 20cm ($.90). Along with these blocks I would install steel reinforcement, re-rod, of 3/8" ($3.51) and for columns 1/2" ($6.24).

 

Another product available here is SuperBloque. This product is basically an over sized block that the local tradesmen do not like because of its weight and bulk. When a mason is installing these blocks the labor is complicated by the fact that each block must be lifted on top of the previously installed blocks and it is more difficult than regular sized block. Therefore the fit and distribution of concrete mortar is sacrificed for less quantity of blocks. The width and strength of the vertical steel reinforcement rods (columns) which support the block wall system and horizontal concrete support system (headers) that will support the roof structure that are part of the SuperBloque package are only 1/4". These thin steel reinforcement rods and the smaller poured concrete columns that will support the entire structure are marginal and in the event of seismic movement would give out much sooner that a larger vertical steel reinforced column construction system like I install in my traditional concrete block construction method.

 

The additional hassle of using the SuperBloque is that they only sell them through a few distributors by the square meter ($25.75 m2) including the steel reinforcement, re-rods, which are only 1/4" ($1.27) and in my opinion are inadequate.

 

Traditional vertical concrete support columns are 12" x 8" and reinforced with six 1/2" thick steel rods and then the horizontal support headers are 12" x 8" with six 1/2" steel rods. There is additional labor involved in order to assemble the steel reinforcement and install the quantity of blocks used in the traditional construction method but the tradesmen are familiar and accustomed to this method and therefore take pride in the quality of their installation therefore the consumer receives a higher quality finished product. I sleep much better at night knowing my building structures are anti seismic and do not develop fissure cracks prematurely which require much more maintenance for the owners. As was discussed in a previous posting, painting and preparation of poorly installed concrete surfaces is not only expensive but also unsightly until repaired.

 

I have close up photos of all the above construction methods as well as the Endless Beach Condos that were taken on July 23, 2007 on Potrero Beach, Guanacaste that I would be happy to send you offline. I built these condo buildings 50 meters from the salt water of the Pacific Ocean in 1993 and 1994 with the traditional concrete block construction method. In the photos you can see that during the last 13 years they have withstood seismic movement as well as constant salt water and radiation from the sun.

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great treatise Tom and I couldn't agree more - when we first started building here in Costa Rica we would take competitive bids between block, superblock and pre-fab concrete - after some both positive and negative experiences, we concluded that any money saved was insufficient to offset the headaches and heartaches of trying a "new approach" in CR, and we have simply used standard block construction from that point on ...

 

let me call on your CR HomeBuilder experience and expertise for a problem we have -

 

on one of our projects the owner selected a bathroom floor tile made in Spain and it is extremely slippery to the point of being hazardous in my opinion - I have used this same brand tile in Europe without difficulty and the manufacturer informed us that the export version has an extra glaze coat for long term appearance - they don't admit to the hazardous possibilities and we have no recourse in a practical sense

 

we had a similar circumstance in the states some years ago and solved the problem with an acid bath using Oxalic acid - the problem is I can't find Oxalic acid in CR and import is not feasible - I don't think Muratic is strong enough to cut the glaze and Muratic tends to "cloud" finish in any event - so, do you have any suggestions based on your experience and expertise here in CR short of the dreaded non-slip strips

 

will appreciate any assistance you may be able to send this way, and of course, solicit a decent solution from others who have had and resolved this same problem using products available here in Costa Rica

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I have done a lot of work to install new floor coverings on top of existing tile floors where we "roughed up" the surface of the tile with a diamond plate on a floor buffer. But what you need to do is refinish this tile so it appears new without the slippery glaze. In the real world there are many diamond abrasives of various types and coarseness that could be used. Starting with an aggressive segmented metal bond diamond for cutting through the undesirable glaze, followed by a series of resin matrix diamond abrasives ranging from 30 to 400 grit for smoothing, honing and preparing for the final polishing process.

 

Keep in mind that once you allow someone to refinish the ceramic tile it can be easily maintained but it will require professional periodic buffing.

 

The southern USA is full of old time terrazzo floor refinishers who could probably complete the work you need done. Unfortunately the equipment is heavy and expensive and requires a lot of periodic maintenance.

 

Seems like very risky work down here in the jungle, when you consider the potential damage to the entire ceramic tile floor and the periodic polishing that it will need. Is there a small closet or area where someone could experiment and not damage the entire floor?

 

I'll check with my Costa Rican hardwood floor refinishing technician to see if he has any ideas. How many m2 of ceramic floor do you need to refinish?

 

PS: I have always been told that when you use acids on ceramic tile floors you run the risk of etching and the floor can become porous. But since you've successfully used the Oxalic acid bath you know what needs to be done. You're right that Muratic acid is not strong enough. I use that to clean cement and much abrasion is needed for the Muratic acid bath to achieve results.

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we have about 25 m2 to fix and yes, we do have an area to experiment -

 

thanks Tom and let me know what your experienced guy says becuase obviously, we cant to the high maintenance reglaze

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I met with my hardwood floor tech and he felt confident that he could use his floor sander and edger with a fine #50 sand paper to remove the glossy glaze from your ceramic tile. His minimum fee to complete this work is C60,000 within the central valley and he charges an additional C20,000 to travel outside the valley to areas like San Ramon. This floor technician has been working with this floor sanding machine for 15 years and knows his business very well. After meeting with him and discussing the work, I believe with his experience he can accomplish removing the coating. You could direct him to begin in the small area that we discussed initially and if the work looks good then he can continue to complete the entire ceramic floor. Any additional sealer application you may want to apply will be your responsibility. His minimum fee is to cover bringing his large sander and edger to your site to complete the work. He will need to get paid that entire minimum fee covering transport of the equipment weather or not you direct him to complete the entire floor. Let me know if you would like his name and contact info.

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good afternoon Tom -

 

I really appreciate your input and your floor guy's confidence - I think I will get my contactor to try the sample area and if we can do it here, then we are listo - I'll let you know if we need your guy to hold our hand and also our results

 

thanks again señor DonTom

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Question: What would you say to those that would argue that concrete block as a building material is not ecologically sustainable?

 

I know that Habitat for Humanity is looking to replace concrete block as a building material for this reason. I do not know the specifics as to precisely why they have come to this determination. I am curious as to what the environmental arguments are for concrete block as a building material, both pro and con.

Edited by Kahuna

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Question: What would you say to those that would argue that concrete block as a building material is not ecologically sustainable?

 

I know that Habitat for Humanity is looking to replace concrete block as a building material for this reason. I do not know the specifics as to precisely why they have come to this determination. I am curious as to what the environmental arguments are for concrete block as a building material, both pro and con.

 

I'll ask again. I don't have an agenda, I would just like the information. Thanks!!!!!

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I'll ask again. I don't have an agenda, I would just like the information. Thanks!!!!!

 

Another building material question: Does anyone have any experience with Recycled Plastic Lumber, specifically for exterior decking. Cost vs traditional lumber...availabiltiy in CR ??? I have been unable to find any info at all. We are planning a large front deck to our house in CR and would like to use a more eco-friendly "green" solution if possible. I am thinking it may be cost probitive. Any or all opinions and experience are welcome! Thanks in advance! jean

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BobC

Looking at your post date, this might be too late, ...Don't waste your time, and money trying to make the tile slip resistant...the diamond pads will only show scratches, and ruin the glaze...I have had good luck, even on polished granite shower floors, with Miracle's Porous Plus...I'm speaking from years as a tile contractor, and granite slab fabricator...I have a link at the end here....I would be happy to bring you down some, but it won't be 'till Spring...

http://www.miraclesealants.com/s_porous_plus.html

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Good morning PVA and no, it is not too late as our "sacrifice" testing only worked when we severly scratched the finish -

 

don't know if you would be allowed to bring this stuff along, being a chemical composition, but I will contact them to see if they have a distribution setup in Central America or CR

 

send me an email so I can keep in touch while checking this out please - and Thanks again , this looks like our solution

 

any idea offhand what coverage is per gallon per application ? we have 7 bathrooms and each one is about 80 square feet

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Good morning PVA and no, it is not too late as our "sacrifice" testing only worked when we severly scratched the finish -

 

don't know if you would be allowed to bring this stuff along, being a chemical composition, but I will contact them to see if they have a distribution setup in Central America or CR

 

send me an email so I can keep in touch while checking this out please - and Thanks again , this looks like our solution

 

any idea offhand what coverage is per gallon per application ? we have 7 bathrooms and each one is about 80 square feet

 

 

Bob,

Sent you an e mail...

Colin

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