Mako

Thanks, I live in a Timberframe house currently, just asked another member to give more info on Twinwall, not come across it yet. But timber frame house I live in, friends who build few, what I seen and read, constant movement, every spring and autumn, Its getting too much. I said never again, but I’m still considering. also price, so far it seems timber frame is not the cheapest way to build, but in terms of performance, behaviour I’m yet to find a reason why people doit? Is it lack of knowledge or laziness to find better ways? what is your view on Timberframe or what system would you use and why?

Thank you, I’m trying, gets frustrating at times, to sieve through all the contradicting information ain’t easy. I wish there was a guide here, similar to cars you buy Merc and you pay over the nose but you will appreciate quality, or buy Tesla and it will give you low running costs, or Buy Dacia it will get you from A to B but not in style and it might break few times before you get there. Not easy is there a tread where guys talk about calculating/modelling? Is there this kind of knowledge between members?

Thank you really appreciate your input, so you combined the concrete in the basement and timber frame on top. Could you send a cross section of the Timberframe wall please. Not sure I seen twin wall yet.

I’m trying to understand why, are we all building Timberframe if we all can see the problems. Is it because of price? Easy and familiar methods of construction? I’m not saying concrete, but why Timberframe? I want to build a house that works, I was recommended to join in here for help, and than advised to do my own research, im just confirming the knowledge, by no means I’m trying to be rude, sorry if it comes across like that. There is no consistent information out there, hence it raised a lot of questions.

Interesting, would you be able to calculate how much external energy is needed to increase temperature of concrete 1m x 1m x 0.15 to 25C originally heated to 21C, so 4C difference? Solid concrete face wall insulated from the outside. Is that possible?

Water in insulation defeats the object. Water has a good heat transfer rate, point of insulation is to slow it down. its better having no insulation versus wet insulation.

In that case I don’t know what insulation I had from Celotex that have got soaked through when left outside, it was foiled on both sides. in terms of Off gassing, you can get PiR boards with plasterboard bonded to it, located internally in the rooms. also I read somewhere that this off gassing causes PIR to reduce performance as a result of Off gassing. takes about a decade to reach performance Of standard white EPS. What are your thoughts on that? you mentioned raw material, I don’t believe there is a formaldehyde in woodcrete products like Durisol, Isotex or Velox. Also if you have solid concrete structure and insulation from the outside, say XPS you don’t have to worry about those things. osb, MdF laminated woods you don’t need in your house, you van get 0 VOC paints etc, so you can minimise that part. modern buildings should not use such materials that carry health risks, especially as we know about them

Yes, if concrete has got the capacity to store more energy, if will prevent sudden changes in temperatures caused by solar gains. if we are talking about Passive House with all the limitations of window openings, sizes etc you are probably right. But if you want to enjoy life and views etc, you have to calculate with some solar gains. What is the best product to deal with that, would that be Concrete? Or Timberframe House with no thermal mass? i think my point is, when you get solar gains in Timberframe house your house will overheat and you need to dump the heat otherwise you will have 30C in the house before you know it. With concrete and the mass charged to say 21C you still have capacity to sink the heat into it, even if the temperature of the concrete increases by few degrees that’s better than 30C plus. i understand that there is conection between the amount of concrete in the build and amount of solar gain, but this can be calculated And designed out. It’s harder to design it out with Timberframe unless you remove windows and stop all solar gains. Am I correct thinking this way?

understand the vapour diffusion process, but how does that work with loose fill celulose? what system delivers permanently perfect airtight house and have little vapour resistance? Ok, if that was the case, me thinking, how can the external air heat up, if cellulose is really good insulating product? There would have to be great heat loss for the air to heat up and diffuse the moisture out before it entered the cellulose. considering that we are all designing homes to 21C internally, that means the summers we had in the last 5-10 years, with temperatures gradually increasing while the external humidity is still high, would therefore push the moisture into the dry cellulose and germinate Bacteria, mould and rot of the OSB boards timbers, and we can’t avoid that. Again in Scandinavia with dry air, low humidity and extreme temperatures it could work, but I’m not convinced same would apply here. I’m asking for more convincing information, in order to make an educated decision.

Agree with you Gypsum in the mined form has density like that, but in Plasterboard it has been cut, and added other cheaper fillers, to make it lighter for transport, and cheaper to produce, you get 500-1000kg/m3 of plasterboard getting closure to wood, which is classed as insulant compared to concrete. PIR leave it outside in the rain and see in the morning, also it states on the manufacturers website keep dry. it burns, we seen the tower block going to flame because of it. it also emit gasses into the households and nobody minds, crazy stuff if you look into it.

I understand what you saying, but I still find that if the external outer skin lets vapour out it will let it in as well. for example today we have 93% humidity level here, the humidity will get into the timbers of the i beams, OSB it’s like a wheatabix when wet, cellulose the same, how is that protected? understand if you use polythene you will stop the vapour going into the wall, but increase the humidity internally relaying purely on ventilation to maintain the balance. I think wall should be breathable to a degree but if there is vapour passing through none of the elements should be affected by it. Would you agree? what is classed as build quickly? Most of the time the timber kits are build within 3-5days and than waiting open for 4-12weeks waiting for Windows. thats if it doesn’t rain during construction, or transport. I was more referring to the entire structure, Roof, tiles, sanitary, cables, plastic ducts, plasterboard, membranes, tapes, insulation etc more often you need to replace the building the greater impact it has. take your point on the soundproofing, but not convinced, friend had used wolf joists with metal zig Zac in roof construction, blown up with Celulose, And you can hear everything outside. Membranes both sides, Slate tile, plaster boarded internally. Internal insulation, many people use insulated plasterboard internally, poly ICF systems have internal insulation, Timberframe would be classed as internal insulation, not having the thermal mass present. I think guys with concrete houses are reporting minimal overheating, timberframe Houses overheated almost every day Last summer we had. There is nowhere for the heat to go, other than open windows, and let the free energy you gained go to waste. Why can’t we utilise this energy? I’m led to believe that concrete or house build from solid Plaster are the way to go. in terms of the tapes, that is proven, when people do extensions, and open the walls, it’s unbelievable membranes pulled apart, it’s a fact. in terms of PIR, the same it doesn’t perform when wet. Do a test put a board outside and see how much water it absorbs. XPS you can class as closed cell insulation, I believe. PIR also burns - Look at the tower block disaster in london Celotex was used if I’m correct. Im trying to find the holy grail of a building the performs and lowers running costs, without additional problems. similar to Huff Houses, friend did few repairs on one and found Mouldy areas under the roof. that just points to me that these types of structures are just not cutout for the humidity levels we have here. different in Alps, Scandinavia, Russia where they have low humidity, minus 20-50C and all bacteria/mould growth is killed every year. In here we just keep breeding the mould, breathing it, no wonder we have health problems As a nation. Same applies to turning off MVHR, what is going to happen to humid ducts without the airflow? grow mould as it happens, what happens when you turn it on? The mould is blasted into the house where people live. not good at all, if you have it keep it running

I’m learning, thank you for explaining, that makes sense. In your opinion with exposed concrete, hoW long would the heat from solar gain take to get absorbed by the concrete, and how long would it take to release? I would think that it would be simultaneous as the solar gains are raising the internal temp, the heat is gradually absorbed into the concrete. depending on how much Heat capacity the concrete or wall product has will determine how soon it will overheat? Do I understand it correctly?

What type of construction have you used?

how long have you had it off? you need to watch for the mould growth in the ducts, be careful, better get them cleaned.

another think i read, you only need Mvhr system if you have very good airtightness, if the airtightness is not great you get away with trickle vents, but the whole point of mvhr is to bring fresh air and reuse the existing heat. i thing i will be putting one in. great in the summer you turn the recuperation off just have the fresh air coming in, keeps the building cooler. but it needs thermal mass, in houses with internal insulation it won't help, it will still overheat apparently.

if the vapour can get out of the cellulose from inside out, there must be reverse as well and the cellulose can get wet. how does cellulose perform when wet? internal airtight membranes, the only weakness is at the joint, can you find out from any supplier how long do they guarantee the membranes to work? they have to guarantee for 10years, what happens after that? membranes coming apart within the wall? plaster boarded skimmed and decorated? where is the vapour going to go? into the cellulose or PIR insulation, not talking about flammability at this point, but how is PIR insulation performing when moisture get in? Fruit for thought....

I understand and agree that we all make choices, but even I beam is less stable than concrete? Less soundproof? And less airtight? And won’t last as long? Will also have negative effect on land fill when it comes to rebuild. And probably more expensive as well to start with compared to concrete, my thoughts...

I have read it yesterday, I think Jeremy got it slightly wrong. if anything Gypsum has got insulation property to it, he based is calculations per KG, instead of m3, imaging how much volume is 1kg of wood, and how much volume would be 1kg of concrete. its all about density of products. Simple float test should give you an idea. water - 100mm cube is 1kg wood - soft dry wood used in construction 100mm cube - would be less say 0.4kg concrete - 100mm cube - depends on type say 2kg now you apply your Jouls per kg and see where you get. Do you get my drif?

Interesting, would you be able to provide a detail?

Thanks, you mentioned that energy saving capacity is reduced, but if you have solid concrete on internal side, you are using the 100mm to your advantage and any more is at reduced performance, happy with that? That means there is a saving energy with concrete. if the concrete provides the air-tightness, and there is solid insulation applied externally? Would that help? surely when we talking about vapour resistance to be greater, that means there won’t be any air-tightness in the house? If the vapour can escape? That means the wall is air-permeable, how are you going to keep the heat in? I might be wrong, just thinking out loud

Hi, not sure I’m following, I been told that concrete stays the same temp all year around, at least that’s the aim. that needs to be controlled by external blinds to stop overheating. More concrete you have in the house the more heat capacity the house can deal with. On the hotter days, it will stay cooler for longer. That’s my understanding. The insulation in my head is really important as it stops the heat getting into the concrete from the outside. If you have no insulation, your house would be like an oven in the summer, And Cold in the winter, hence it will take too long to heat up in the winter, and impossible to cool down in the summer. Apparently For the concrete house to work it needs to be balanced right. im still looking into it, but it starting to make sense more I read about concrete homes

i think we are on the same page... i don't think that strictly speaking PH needs to be of 21'C, i think you can control the temperature, in a concrete house if you wish. design it for 18'C and when need it put a jumper on. my wife's preference is 25C all year round

my only worry with that system is due point reaching into the cellulose layer and creating condensation issues, mould growth, etc how is the cellulose dealing with that? speed i take your point, but building timber frame in this climate/humidity is challenging to keep the timbers dry as soon as they come out from the factory the humidity is at it. by the time you get it watertight its too late. i know i live in timber frame house and i swore never again. constant movement 2 a year a need to go around and fix cracks and decorate. i also read somewhere that air-tightness is compromised after some time when the membrane joints start failing. don't get me started on PIR insulation not fit for purpose. sorry for the moan im fed up with this house. as the blockwork doesn't deliver either, the only option is concrete, unless you know another alternative.

thank you for correcting my terms, im not an expert, im trying to decide which method to use to build my next house. what happens if you use concrete in walls and suspended floors? if i understand your calks you converted walls only do we anticipate heating the concrete mass by solar gains in the winter? I believe the heating load should reduce as well, am I wrong thinking that? sound proofing, I thought soundproofing is also improved by concrete, living in timber frame house now, I can hear everything through the walls. sustainability point of concrete v timber, if you look at the life span of timber frame builds being around 50years, concrete buildings are here already for hundreds of years. surely concrete must be more sustainable compared to timber.

i would love a lecture, but so far using common sense