Critter protection of wood beams

We are renovating an old farmhouse in Andalucia, Spain, and the roof beams need replacing (we are reusing the tiles, but adding a permeable membrane and insulation). The old beams were all but eaten up by whasps. There are also termites in the area, but I don't expect them to be a problem in the roof structure (as the rest of the house is made of stone). So whasps, carpenter bees and maybe woodworms are our primary concern. We have reasearched wood protection, but can't seem to find anything? We know that we can use linseed oil or tung oil mixed with bees wax and terpintine - but we don't know if that only protects against weather or if it also protects against critters.

Any input would be greatly appreciated

No that doesn't do the job. Actually all chemical solutions weather it is linseed oil or some toxic stuff does leach or gas out over time and becomes less active. Timber that is dry and well aerated seldom gets critters. For the wasps I would look how they entered. I would as well ask a local carpenter, it might save you a lot of money and you have local long standing advice.

We did this last year and painted all the wood with a borax solution.

Edit - the thread is in dire need of updating, but there's loads of photos of our roof project here - Replacing the Roof

Another edit - another thread of interest Preserving roof timbers

Borax us strictly forbidden to use as a domestic pesticide (or at all?) in the EU. I

My problem with asking a local carpenter is that the Spanish have no problem what so ever using extremely harsh chemicals... Actually they swear by it
So I'm looking for a non-toxic solution.

The wasps came in through broken windows so that is pretty easy, they will not likely get in as long as we live there (if they do we will notice, and can take immediate action). The under-roof is another case - it is well areatet, but that also means the wasps can get in. We were talking about putting a wire net in the opening to prevent bats and snakes from climbing up there, if it is fine enough it will prevent wasps and carpenter bees as well. The wood we use between the upper roof and under roof is heat treated, so it will not be harmed by the weather.

Hi Dawn, et al.,

Borax (Na2B4O7 • 10H2O) is a natural mineral. and in this application is more fungicide than insecticide.

Boric acid (H3BO3 (sometimes written B(OH)3) ) is derived through chemical action from Borax, and is a natural insecticide, as is diatomaceous earth.

Both are available and widely used everywhere, including the EU. Dawn you will have to expand why you didn't think it could be used in the EU, perhaps you have confused it with something else? I know in Spain they still commonly use DDT reserves and Dursban as well.

Regards,

jay

It's certainly still for sale in Portugal, and also on amazon.co.uk. I bought a 25kg sack of the stuff last year as it was all I could find, but since then I've found it in smaller bags.

From Wikipedia:
"Borax was added to the Substance of Very High Concern (SVHC) candidate list on 16 December 2010. The SVHC candidate list is part of the EU Regulations on the Registration, Evaluation, Authorisation and Restriction of Chemicals 2006 (REACH), and the addition was based on the revised classification of Borax as toxic for reproduction category 1B under the CLP Regulations. Substances and mixtures imported into the EU which contain Borax are now required to be labelled with the warnings "May damage fertility" and "May damage the unborn child".

My friend, who is an environmental chemist told me, and sent me an article concerning it a few months ago. I can't find the article right now but have written her.

I don't know why you can still buy it, I suppose that it is not all use that is illegal? But either way, even if DDT were still legal, I wouldn't use it

Hi Dawn,

Borax is toxic, as is anything in an atomized or "dust" form, even talc and wheat flour are toxic in this state of condition. It is still for sale in the EU because even in the citation you shared, the description was for a "warnings only" among pregnant women. A "warning" is different from "illegal" or "dangerous" or "extremely toxic" designation by rule of law (and common sense application.)

I will say that in it's natural state, or as normally used (20 mule team laundry soap is almost pure Borax) it is safe to use even if you are pregnant. If you are chemically sensitive however, enough to have reaction to Borax in any of its forms (some rare individuals are reactive to even this type of natural mineral) then you will not be able to go to the ocean either, as it's salt matrix will cause reactions. Sea water and borax in an atomized and inhaled conditional state share about the same levels of toxicity from a biochemical or physiological perspective. So as with any "pure form" product be it diatomaceous earth, wheat flour, or borax, treat with caution and common sense.

I would not use most of the chemical products available in the pest control industry legal or not. Mineral, botanical, biological and exclusion are the best forms of pest control in most cases.

For now - I'll take my friends word for it, and not use it

Dawn - if there's any way you could get a link to the article I'd love to read it. Until now we've been happy to recommend borax for wood treatment, but not for laundry or dishwashing where there is a grey-water system as the concentration is then too high for plans. If there really is cause for concern, we will have to re-think our policy.

So are you looking for 'treatments' for your wood or physical barriers to insects?

I've written my friend to resend me the article - I'll forward it as soon as she replies (though I don't remember if it was in Danish or English). One of the things I do remember is that the household use was forbidden because it solidifies in the intestines of any one who might eat it, and the security precautions taken in the home is not sufficient and that it is an estrogen-like substance or something like that.

I think that we will go with a preventing entrance - with a net in front of the opening between upper and lower roof. The beams on the inside will be painted with olive oil and sealed with beeswax, doors and windows with thung oil and beeswax. I frankly think that the reason the roof fell down is that it hasn't been maintained for 30 years.

Dawn Hoff wrote: I frankly think that the reason the roof fell down is that it hasn't been maintained for 30 years.

In Portugal (which is right next door to Spain in case anyone reading this didn't realise) the life expectancy of a traditional roof is only around twenty years.

Hi Dawn,

I usually don't have to go this far into validating myself or the recommendations I make, but in this case it would seem germane.

Dawn, I want you to do whatever makes you comfortable, but following misinformation or methodolgy is not recommended and the only reason I speak up. I can not let poor or inaccurate information slip past me.

For the validation part, I am a traditionally trained Timberwright and Guild Artisan, promoter of Natural Building modalities, (google Jay C. White Cloud) and Historical Restoration Artisan. I am also a former State Supervisor in Commercial and General Pest and Wildlife Control, so I am rather fullent in the "positive and negative" aspects of the industry and it's use of chemicals.

I do not want any reader of this post thread to believe they are going to exclude any species of Dermestid (or general Coleoptera) from attacking there wood work, clothing or furnishings, by "exclusion techniques" such as screens, or as you put it,

"with a net in front of the opening between upper and lower roof."

or using simple "botanical" agents, such as olive oil, tung oil, or beeswax. It isn't going to happen or work, period. It simply will NOT have an effect on these little fellows. You must have an intimate relationship and knowledge of the their biology to be even slightly successful in their control or eradication from wood. I would further point out that Hymenoptera control is very challenging for even us professionals and requires due diligence by the property owner. Most are harmless in your region of Spain as far as the timber frame structure is concerned, other that European Carpenter Bees (Xylocopa ssp) that will require some maintenance work with keeping them at bay, and the wood rendered with treatment and/or proper oils.

https://www.google.com/search?q=european+carpenter+bee&safe=off&espv=210&es_sm=122&source=lnms&tbm=isch&sa=X&ei=00xgUqiLOoic9QT0oIGABg&ved=0CAkQ_AUoAQ&biw=1280&bih=685

So if you ask what it will take to control them, it's going to take chemicals, either natural occurring ones thus recommended or manmade ones that I do not generally recommend, but do sometimes employ when necessary. The holes you are seeing in the wood, and the frass (wood dust) is the evidence of them leaving as breeding adults, and there is nothing you can do about that, the damage is already done. Stopping reinfestation means a chemical barrier and lowering the moisture content of the wood and humidity levels of the architecture. The humidity levels and moisture will work with most, but not all species of wood ingesting Coleoptera larva, for that you need a chemical barrier or console yourself with them causing damage to the wood in and around your home.

Now for the wood timber frames and furniture we make, the traditional methods we use are a mix of (you will like this Dawn) pine rosin, citrus oil, tung oil, flax oil, and beeswax, (you do not want to use olive oil on wood-other than cutting boards as it is a "non drying oil.") Traditional pine tar oils are offend used as well outside. (not coal tars) Added to our oil mix we use on wood is "borate salts" or Borax and other nateral minerals that work as insecticide, fungicide and fire suppressants.

Here is a UK link for a product you can use, that I have used and is toxic by typically not to humans. I do not know the French or German manufacturer name but know they exist and are sold with EU approval. All are "borate salts" based (borax and boric acid) etc.

http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=Tim-Bor%20Insecticide

information:

http://en.wikipedia.org/wiki/Disodium_octaborate_tetrahydrate

Active ingredients: Disodium octaborate tetrahydrate


P.S. Dawn, you are also probably correct in the fact the timber frame structure of your roof was compromised by the beetle infestation and collapsed because of poor maintenance. Part of a home/architectural maintenance program is proper (but safe) pest control management that you can do yourself, you do not need to hire someone in most cases. Use chemicals wisely and safely or pay the consequence either in your health or the loss of property, [ i.e. botanical (garden) or structural (house, clothes and furniture.)]

Few more clarifications....

Coconut oil is the best for cutting boards, it is what we use in the Abattoir.

Carpenter bee damage is the chewing of the nest chamber by the female bee. The tiny holes in wood are from the beetle larva leaving the wood. Ants (actually a wingless was) don't eat wood that is not already damaged. Termites can only be chemically controlled and are very damaging.

Burra, there are traditional wood (timber frame) roofs throughout Europe, (including Spain and Portugal) that are over 500 years olds (some over 1000 years.) Maybe new homes need there wood roof timbers and beam work replaced every twenty years but traditionally built roofs do not. Perhaps you meant the roof covering, but even then a tile or stone roof should last a minimum of 300 years or longer.

The use of Borax is not restricted anywhere within the EU.
It is still used in cosmetics, including diaper rash ointments!
What has changed however, is the labeling requirements.

It appears that the labeling changes were pushed into action by multi-national chemical corporations who want to frighten people away from common and inexpensive 'home brew' concoctions.

Further reading here will help how this all came about:
http://ec.europa.eu/enterprise/sectors/chemicals/files/docs_studies/final_report_borates_en.pdf
http://www.mtib.gov.my/techalert/3-2007/RioTinto.pdf
http://mistralhowto.blogspot.com/2012/06/is-borax-about-to-be-banned-in-uk.html

And to show that it is still readily available: http://mistralni.co.uk/products/borax-sodium-tetraborate-decahydrate

John P, thank you so much for that info and clarification.

I, for one, really appreciate it.

Also, if my information ever seems strayed or out of context, please real me in or ask for my clarification, I will always do my best to comply.

Again thanks for the info and links...Glad to know you out there reading and watching

Thank you very much! I really appreciate your Info and will read it in the next few days.

Just one more question then: The wood between the upper and lower roof is heat treated, will it need more protection than that?

The wood between the upper and lower roof is heat treated

Hi Dawn,

What do you mean by "heated treated?"

Who told you it was and by what modality did this take place?

What was the purpose?

What is the pitch on your roof?

What is the roofing material?

What is the circa date and architectural type for your home?

You reference an upper and lower roof assembly, is this a "cold roof" design or some other two strata roofing system?

Regards,

jay

I just need to say that English is not my first language and I haven't had experience with building roofs before So I have most of my knowledge in Danish, partly in Spanish and partly in English... A bit messy... Even in Danish I sometimes mix up some of the words...

The house is ca. 200 years old. The pitch of the roof is ca 30 degrees. There is a bearing wall in the middle of the house which will carry the beams.

The old roof was made with raw beams (don't know which kind of wood), cane (pampas grass is my guess), some kind of mortar (dirt and lime) and terracotta tiles. The only thing we can reuse is the tiles (and we have found a place where we can buy extra quite cheap).

The normal way to build roofs now in Andalucia now is concrete beams, flat concrete tiles, cement and a concrete tile on top. The houses are notoriously cold in winter and steaming hot in summer...

We will do: Wooden beams - rafters(?), ply-wood, semipermeable membrane and laths (?) one set on top of the rafters and one set across - to make room for air between the tiles and the membrane. The old tiles will be hung on the laths with tile clips on every third tile.

Underneath the plywood we will use a single layer of insulation, which exactly haven't been decided. We also have not decided whether to add another membrane (in Denmark you use 300 mm rock wool and a membrane 1:3 in).

The wood we use for the laths are bought heat treated. Or the ones on top of the rafters are repurposed heat treated pallets and the others we actually did not intend to treat, but as I read it now we should probably use a borax solution on them or buy heat treated laths?

I Danish the plywood+membrane is called and under-roof and the tiles are the upper-roof. It is a double aerated roof.

http://www.texsa.com/es/sistemas.asp?ficha=23a

I can see that you are also discussing this with my husband in another thread, maybe we should keep it to one thread?

Discussion with my husband: https://permies.com/t/24462/timber/recipes-treating-wood

Jay C. White Cloud wrote:
Burra, there are traditional wood (timber frame) roofs throughout Europe, (including Spain and Portugal) that are over 500 years olds (some over 1000 years.) Maybe new homes need there wood roof timbers and beam work replaced every twenty years but traditionally built roofs do not. Perhaps you meant the roof covering, but even then a tile or stone roof should last a minimum of 300 years or longer.

I dare say there are, but the 'rural' properties in my area, and possibly in Spain too, are usually done like this.



As Dawn said, concrete beams are becoming the norm to prevent the frequent renewals needed with the 'raw beams'. These beams in the photo were eucalyptus and were probably 25 years old - the owner said they were 'new', but he was in his nineties when he sold us the place so his judgement might have been a bit 'off'. I think these beams were 'home grown' and suspect that the locals would have used home grown pine before eucalyptus was introduced. Tiles are generally re-used, but in our case there were too many broken ones, too great a mix of styles which didn't quite fit each other, and all of them were old and a bit crumbly so we replaced the lot.

Exactly like that. Our house, just has a wall in the middle.
The lengthwise space in between beams is filled up with the cane/pampas grass and covered with mortar (I assume earth and lime) on the inside and the tiles are "glued" on the beams with the same mortar on the outside.
I'm guessing that our old roof is about 35-50 years old. It's collapsed in several places mainly because the rafters have been eaten up by critters. But where it's still intact I'm amazed that it's still waterproof.
For our new roof and the house in general we are trying to achieve a balance between resource use, health and economy. I don't like the way they do the roofs in Spain, it's basically just a concrete sandwich with tar paper in between. I'll admit, that this will probably last a long time, but I'm not to sure about the health of the indoor climate in the house.

I've found it - but it is in Danish.

I just want to say that I am not questioning any ones knowledge or competences.

I have been wondering about this since I started making my own detergent There is a discrepancy between the fact that all my american "crunchy mom" friends use it, and all my Danish crunchy friends are strictly against it. In Denmark Borax is on the list of "unwanted substances" - but I don't know exactly what that means (will investigate). But I was quite surprised to see it mentioned in a Permaculture forum.

It is not illegal to sell in the EU - but it is illegal to market as a biocide.

Press release from the Danish department of environment:
http://www.mst.dk/Virksomhed_og_myndighed/Kemikalier/Nyheder+kemikalier/06_07_08/Klassificeringen+af+en+raekke+stoffer+skaerpes.htm
"Borsyre og borater
Danmark og Frankrig kom samtidig med forslag til en klassificering af borsyre og borater, som ikke tidligere figurerede på bilag I. De skal nu klassificeres som skadelige for forplantningsevnen og for barnet under graviditeten."
Translation:
Boric acid and borates
At the same time Denmark and France suggested that the classification of boric acid and borates, which did not previously appear in appedix 1. They are now classified as harmful for the reproductive abilities and for the fetus during pregnancy.

Press release from the Rockwoll foundation:
http://www.rockwool.dk/pressemeddelelser+og+nyheder/pressemeddelelse?dkpress=4040
The report concludes:
"-at det ifølge EU-lovgivning er forbudt at markedsføre borsyre som et biocid, altså med effekt mod skimmel, bakterier, råd, mus og rotter mv.
-at det nu markedsføres til ”gør-det -selv” segmentet. Rapporten viser, at der ved privat håndtering er mulighed for overskridelse af grænsen for ”tolerabelt dagligt indtag”. Samtidig vil der hos private, som ikke nødvendigvis skaffer sig af med tom emballage med det samme (hvor der kan være rest af Borsyre krystaller), være risiko for at deres små børn kommer i kontakt med pulveret, som er dødelig hvis barnet spiser blot få gram (2 teske fulde).
-Rapporten sætter spørgsmålstegn ved, om man kan tillade sig at kalde sit produkt for ”grønt”, når man tilsætter 5% af en mulig fosterskadende flammehæmmer, som er lige under grænsen for faremærkning af produktet."

Translation:
- that it, according to EU-law, is illegal to market boric acid as a biocide, ie. with effect against mildew, bacteria, rot, mouse, rats etc.
- the it is now marketed towards a "DIY" segment. The repport shows that in private handling it is possible to override the limit of "tolerable daily intake". At the same time there will, with private users whom not nessesarily rid them selves of empty packaging (containing crystals of Boric Acid) immediately, be a risk of small children getting in contact with the powder, which is deadly if the child eat only a few grams (2 tea spoons)
- The report questions whether one ethically can call a product "green", if one adds 5% of a possible fetus harming flame inhibitor, which is just below the limits of a marking of "danger on the product"

The product mentioned I think is the Paper insulation marketed by Rockwoll them selves, which contain 5% boric acid as a flame inhibitor.

Hi Dawn and Marcus...please see your other post for my responses...

Thank you for all your help