Elimination of Steel as part of a Home’s Structure
Laminated Wood or Bamboo beams for rafters and joists.
These are a far superior solution for structural needs that although be it rare in Costa Rica, is far more economical than steel, incredibly strong, much more stylish as well as a far better environmental solution. Eg. 1 cubic meter of wood consumes one ton of CO2 when growing versus steel that creates 1.8 tones of CO2 hence the impact is almost triple in difference. Aside from that lets look at the other benefits just bare with me as this requires a detailed explanation so as to understand just how this makes an excellent option for well informed consumers..
Glu-lams as they are called, is a very common solution in North America for building excellent structures but few use them in Costa Rica due to both the level of ignorance of the application of such as well as known availability. You do not just go grab them from the local fereteria!
We have adopted these as our own preferred structural material for our own homes for the following reasons as well as offering such for sale as well as our consultancy to consumers who seek superior solutions in both quality, price and as a green building method.
We are also just in the process of incorporating the use of bamboo as well since there is huge tracks of bamboo inventory available which is substantially stronger than wood, grows much faster (4-5 years) and consumes as much as 4 times the CO2 hence it makes an ideal construction material. The harvest of bamboo culms does not affect the plantation at all since we selectively harvest only the mature leaving behind all the immature culms and of course the root structure that can continue producing bamboo crops for up to 120 years. This means there is no environmental destruction in the harvest process at all plus no erosion to precious soil structures can occur which is very critical in flood prone areas and mountainsides. Plus we get a beam substantially stronger than both steel and wood.
Available materials suitable to make Glu-lams are bamboo as well as the hardwood species of teak and cedro all of which have the common critical characteristic of being termite safe materials that are not suitable lunch material fpr this army of enemies.
Comparing Glu-lams to Steel:
For those who would otherwise be considering steel for a roof/floor structure as an example here is a simple comparison. 1 meter of 2″ x 6″ costs $8.50 – $10.00 depending on species versus at least requiring a doubling of purlins would be required to support the same load would cost $8.33. Pound for pound laminated is stronger than steel. Also take note the superior longevity if you are building at the beach where there is the oxidation factor on anything metal versus wood which is impervious to air born salt. Plus ugly purlin is always hidden away versus wood structures can be accented to add beauty in your exposed roof structure. Go to our renovation page and you can see an example of a Pagoda roof we built in Santa Ana to cover an open terrace. Win the client loves here laminated wood. We find with our clients that this is always a major concern hence the much preferred method.
Comparing Glu-lams to a solid single piece of wood:
There is two issues at hand here, one is responsible inventory management and the other is strength and quality of the final product. First off dimensional hardwoods are getting harder and harder to locate since it requires very large trees to produce such since to cut good 2″ x 6″ (the most common size) takes a tree trunk diameter of 16″ to 20″ to produce good structural material. We are talking about old trees (25-120 years under ideal conditions) which are disappearing quickly hence actually finding it can be difficult and such simply does not exist in young plantations. That is drastically different as compared to using much younger (10 year old) plantation grown trees/bamboo (5 year old) where we only need 1 1/2″ x 3/4″ pieces to make up the lamination stock hence the raw material is muuuch cheaper with a never ending inventory available. As a result of global demand prices for premium wood just keeps going up due to this scarcity hence this wood from older trees costs much more since you are basically purchasing time. It just simply is not responsible forestry management nor economical to take mature hardwoods to use for dimensional lumber. In fact is is basically loco.
Quality – The second issue is solid wood no matter how old it is just is not nearly as strong as a Glu-lam is, in fact it is common to be able to reduce the beam size by 40% when laminated hence we consume way less wood to do the same job. The other big problem is very few sawyers have kilns to properly dry the much thicker woods to make stable dimensional lumber hence it typically shows up on the job site soggy wet as no one is willing to wait the 3 years it will take to properly air dry it. The inevitable result is this, there IS GOING TO BE a number of pieces that are going to come curved or twist or crown after they are installed creating big problems in the structure they are part of. Even with kiln dried materials used in Canada the whole industry has gone away from solid floor joists in favour of laminated, engineered TJI or web trusses that never do this hence no warranty problems for the builder or owner plus reduced timber consumption. Converse to this a laminated beam comes to the job site perfectly straight and six months later it will still be and 66 years later it will still be so. Hence such is much easier for the builder and muuuuch safer for the owner. Also solid materials will always have cracks showing up over time as they dry out and the bigger the dimension the worse it is, versus laminated which will never develop cracks.
Comparing Glu-lams to concrete floors:
For second story floors there is really no option since a concrete re-inforced floor costs $85 to $110 per square meter to construct plus adds a minimum of two weeks to buildout time for a 100 m2 floor. So a lot of money and time spent versus a wood structure will come in at roughly half price and be built 5 to 6 times faster. After the fact wood floors have the desired amount of spring in them to reduce stress on feet and knees as we walk on them as well as being considerably quieter with far less noise transfer. This is very important even on first story floors where the owners want a more forgiving floor to walk upon. Many may choose to cover such structures in mature Tico hardwoods so as to enjoy their beauty for years to come which makes for a much smarter use of mature hardwoods than for dimensional lumber. Also on sloped lots wood is easier and often cheaper to build out on a support structure versus trying to level off a mountainside with sloped building sites. This can make for much less dirt movement and less future water erosion problems. Posts of wood or concrete columns can much easier be built to accommodate such a situation than either cutting into a mountain or building up with fill to support concrete slabs. This also drastically reduces the need for use of concrete hence so reducing it horrible environmental impact as well.
All in all a real win/win/win situation. Better price, better quality, more comfortable home utilizing far superior green building principles.