Unit 3 Blog!

 A Blog Post By Emma Hahn

Wood: the Pluses, the Minuses, and the Neutrals

    Hey y’all! I don’t know if you guys remember my last blog post, but we basically talked about the different types of materials. In this post, we are going to be really focusing in on wood as a biomass.

The Positives :)

    One of my favorite things about using wood as a biomass is that almost all of it gets used! It’s either used as lumber, made into paper, sold to farmers as animal bedding, or used as a way to make energy (Lesson 13). This is great because it means that no part of the tree goes to waste once it is cut down!

A pig who has wood shavings as its bedding.

Another great thing about wood is that since it has been engineered, it can be used for many more things! Cross Laminated Timber (CLT) is an example of wood that has been engineered. CLT is made by bonding wood together in a way that makes the grains alternate (Lesson 15). CLT can be used to make buildings because it can handle weight on all sides. This makes it a more environmentally friendly construction material!

This graphic from Nässén shows the impact different materials have on the environment.

The Negatives :(

Now while it is great that wood is being used as a building material, there are some downsides to it. Wood is not as strong as other materials, and its strength depends on how the force is applied to the wood with respect to its grain. And wood is the strongest when the force is applied parallel to its grain (Lesson 14).

Table 1 from Resilience: Why Material Selection Matters shows the strength of wood compared to concrete and steel.

Also wood has to be dried before it can be used to prevent it from rotting. And if the wood is not dried correctly or to the correct moisture content, the wood may shrink or expand. Another thing that can cause problems from using wood in construction is if the wood is not dried to the correct moisture content for where it is being used. If this occurs the wood may start to warp (Lesson 14)!

The Neutrals :|

The neutral thing about wood is that it is carbon neutral! This means that they absorb carbon during their lifetime, but they eventually release it in the end. Different types of wood absorb different amounts of carbon, which is presented in table 2 from “Carbon in Wood Products- The Basics”.

Table 2: Amount of carbon stored in different types of wood.

       One building that I like to look at is the Dalston Works, which is the largest building in the world made out of CLT. Due to using CLT the company was able to cut down the normal amount of material deliveries by 80%, which lowers the carbon impact the building has, and the building stores 2,886 tons of carbon dioxide (Schuler)!

A photograph of the Dalston Works in London, England.

The Conclusion <3

It is obvious that there are many different aspects of using wood in construction, but how do we know which aspect outweighs the other? When looking at the total effect of wood, it is clear that the positives outweigh the negatives. The main negative of wood is that it is not as strong as other materials; however, this is becoming more and more untrue as wood continues to be engineered so it can better withstand different circumstances. While there is still a lot of work to be done to make wood a better construction material, it is the best option for building once we take the environment into consideration!

Works Cited

“Carbon in Wood Products- The Basics.” Dovetail Partners, Inc., 2013, https://www.dovetailinc.org/land_use_pdfs/carbon_in_wood_products.pdf.

Lesson 13, Forest to Lumber, BBE 1002, UMN

Lesson 14, Moisture and Strength Pertaining to Wood Use, BBE 1002, UMN

Lesson 15, Engineered Wood Products, BBE 1002, UMN

Nässén, Jonas, et al. “Concrete Vs. Wood in Buildings – An Energy System Approach.” Building and Environment, vol. 51, 2012, pp. 361–69, https://doi.org/10.1016/j.buildenv.2011.11.011.

“Resilience: Why Material Selection Matters.” Continuing Education Center, 2018, https://continuingeducation.bnpmedia.com/courses/american-institute-of-steel-construction/resilience-why-material-selection-matters/3/.

Schuler, Timothy A. “Dalston Works, the Largest CLT Building in the World.” Architect Magazine, 2018, https://www.architectmagazine.com/technology/architectural-detail/dalston-works-the-largest-clt-building-in-the-world_o.